CN104811644B - A kind of HDMI transmitters amplitude output signal control circuit - Google Patents
A kind of HDMI transmitters amplitude output signal control circuit Download PDFInfo
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Abstract
This application discloses a kind of HDMI transmitters amplitude output signal control circuit, including：Decoder, for the control signal of state output first or the second control signal according to switch level；Voltage detector, during for getting the first control signal, the voltage difference at detection RL resistance both ends, when getting the second control signal, the voltage difference at detection RR resistance both ends；Comparator, for the voltage difference at the RL or RR resistance both ends and the size of datum；Counter, for according to comparative result control counter value changes；Selector, during for not getting corrected value, according to the output amplitude of Counter Value adjustment HDMI transmitters, when getting corrected value, the output amplitude according to corrected value adjustment HDMI transmitters.When finding that RL the or RR resistance disconnection causes HDMI transmitters output amplitude to reduce, user can send corrected value to the selector, to keep the output amplitude of HDMI transmitters.
Description
Technical field
The application be related to HDMI (High Definition Multimedia Interface,
HDMI) signal processing technology field, more specifically to a kind of HDMI transmitters amplitude output signal control circuit.
Background technology
HDMI has been widely current is widely used in multimedia in recent years as a kind of digitized video/COBBAIF technology
In equipment, for by the communication interface, with high speed from DVD (digital universal disc) logger, set top box or other AV sources (audios
Video source) to television receiver, projecting apparatus or other displays send digital video as uncompressed (base band) vision signal
Signal and the digital audio and video signals related to the vision signal.
In signals transmission, its main relevant device includes HDMI transmitters and HDMI receiver, and user is inciting somebody to action
When HDMI transmitters (hereinafter referred to as HDMI TX) are connected to HDMI receiver (hereinafter referred to as HDMI RX), connecting line is frequently plugged
Differential pair line, socket or plug connection can be caused bad, or even the situation that differential lines disconnect occurs, and then differential pair occur
The situation for having a signal to disconnect, causes the amplitude of HDMI TX output signals smaller, causes HDMI TX and HDMI RX compatibility
It is deteriorated.
The content of the invention
In view of this, the application provides a kind of HDMI transmitters amplitude output signal control circuit to have in differential pair
In the case that one signal disconnects, still ensure that the HDMI TX have the output of higher amplitude.
To achieve these goals, it is proposed that scheme it is as follows：
A kind of HDMI transmitters amplitude output signal control circuit, including：
The voltage detector that input is connected with HDMI transmitters；
For being controlled according to the switch level signal got between the HDMI transmitters and the voltage detector
The decoder of annexation；The decoder, it is used to control the voltage for when the switching signal is low level, exporting
First control signal of the voltage difference at RL resistance both ends in detector detection HDMI transmitters, when the switching signal is high level
When, export the second control letter for controlling the voltage difference at RR resistance both ends in the voltage detector detection HDMI transmitters
Number；
In-phase input end is used to obtain datum, the ratio that inverting input is connected with the voltage detecting circuit output end
Compared with device；
The counter that In inputs are connected with the output end of the comparator；
First input end is connected with the output end of the counter, the second input be used for obtain corrected value c, output end with
The connected selector of the HDMI transmitters；
The selector, for when not getting corrected value c, by the Counter Value that the counter is sent send to
HDMI transmitters so that the output of the HDMI transmitters according to Counter Value adjustment adjustable current source, when getting the school
When c, the corrected value c is sent to HDMI transmitters so that the HDMI transmitters are according to corrected value c adjustment adjustable electrics
The output in stream source.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, in addition to：
First input end is connected with the output end of the counter, the second input is used to obtain latch signal, output end
The adjuster being connected with the input of the selector, for when the latch signal got is high level pulse signal, locking
Present counter value is deposited, is sent the Counter Value deposited as corrected value c to the selector；
Wherein, when the switching signal is low level and counter Counter Value it is stable when, the latch signal is
High level pulse signal；When switching signal is high level and counter Counter Value it is stable when the latch signal be high level
Pulse signal.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the corrected value c includes the first corrected value
With the second corrected value；
The selector also includes correction value selector, for selecting first corrected value or the according to pre-set priority
Two corrected values are as the corrected value c.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, first corrected value is adjuster
Output signal；
The first input end of the adjuster is connected with the output end of the counter, the second input is used to obtain latch
Signal, output end are connected with the input of the selector, for when the latch signal got is high level pulse signal,
Present counter value is latched, is sent the Counter Value deposited as corrected value c to the selector；
Wherein, when the switching signal is low level and counter Counter Value it is stable when, the latch signal is
High level pulse signal；When switching signal is high level and counter Counter Value it is stable when the latch signal be high level
Pulse signal；
Second corrected value is the adjustable corrected value of user's input.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the priority of second corrected value is big
In the priority of the first corrected value.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the voltage detector is subtracter；
The positive input terminal of the subtracter passes through the first controlling switch and the ungrounded end phase of RL resistance in HDMI transmitters
Even, it is connected by the 3rd controlling switch with the ungrounded end of RR resistance in HDMI transmitters；
The negative input end of the subtracter passes through the second controlling switch and the ungrounded end phase of RL resistance in HDMI transmitters
Even, it is connected by the 4th controlling switch with the ungrounded end of RR resistance in HDMI transmitters.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the decoder, specifically for obtaining switching
Signal, when the switching signal is low level, export for control described first and the 4th controlling switch disconnect, second and the
First control signal of three controlling switches closure；When the switching signal is high level, export for controlling first and the 4th
The second control signal that the controlling switch of controlling switch closure, second and the 3rd disconnects.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the adjuster includes；
The first latch and the second latch that first input end is connected with the output end of the counter；
First input end is connected with the output end of first latch, the second input is defeated with second latch
Go out the processor that end is connected, output end is connected with the input of the selector；
Second input of first latch obtains the first latch signal；
Second input of second latch obtains the second latch signal；
First latch is used for when first latch signal got is high level pulse signal, latches this
The Counter Value of Shi Suoshu counters, and latch result is sent to the processor；
Second latch is used for when second latch signal got is high level pulse signal, latches this
The Counter Value of Shi Suoshu counters, and latch result is sent to the processor；
The processor be used for the maximum for calculating the latch result that first latch and the second latch are sent and
Average value, and input the maximum or average value to selector according to preset rules；
Wherein, first latch signal, wherein first latch signal when the switching signal is low level and
The Counter Value of counter is high level pulse signal when stable；Second latch signal is high level in the switching signal
When and counter Counter Value it is stable when be high level pulse signal.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, the selector includes：
First input end is connected with the output end of the counter, the second input is connected with the output end of the adjuster
The first data selector；
First input end is connected with the output end of first data selector, the second input is used to obtain the second correction
Second data selector of value, the output end of second data selector are launched as the output end of the selector with HDMI
Device is connected.
Preferably, in above-mentioned HDMI transmitters amplitude output signal control circuit, including：
The number of the adjuster and selector is N number of, and the adjuster is corresponded with selector and is connected, each
The corresponding HDMI transmitters of selector；
The decoder is additionally operable to obtain period 1 signal, for when it is low level to detect the switching signal,
Exported in first complete cycle of the period 1 signal for controlling the voltage detecting circuit to detect the first HDMI
The control signal of the voltage difference at the RL resistance both ends of transmitter, export during next cycle for controlling the voltage detecting circuit to examine
Survey the control signal of the voltage difference at the RL resistance both ends of next HDMI transmitters；When detecting that the switching signal is high level
When, exported in first complete cycle of the period 1 signal for controlling the voltage detecting circuit detection first
The control signal of the voltage difference at the RR resistance both ends of HDMI transmitters, export during next cycle for controlling the voltage detecting electricity
Detect the control signal of the voltage difference at the RR resistance both ends of next HDMI transmitters in road.
It can be seen from the above technical scheme that HDMI transmitters amplitude output signal control circuit disclosed in the present application,
During the early HDMI transmitters amplitude output signal control circuit normal work, pass through the electricity at the RL or RR resistance both ends
The size of pressure difference and datum controls the size of the Counter Value, and the HDMI is adjusted by the size of the Counter Value
The electric current output of adjustable current source in transmitter, cause HDMI transmitter output signal width when finding that RL the or RR resistance disconnects
When degree reduces, user can keep the HDMI transmitters output signal width by way of sending corrected value c to the selector
Degree.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the required accompanying drawing used in technology description to be briefly described, it should be apparent that, drawings in the following description are only this
The embodiment of invention, for those of ordinary skill in the art, on the premise of not paying creative work, can also basis
The accompanying drawing of offer obtains other accompanying drawings.
Fig. 1 is a kind of structure chart of HDMI transmitters amplitude output signal control circuit disclosed in the embodiment of the present application；
Fig. 2 is the structure chart of HDMI transmitters amplitude output signal control circuit disclosed in another embodiment of the application；
Fig. 3 is the structure chart of HDMI transmitters amplitude output signal control circuit disclosed in the another embodiment of the application；
Fig. 4 is the timing variations figure that level signal is controlled in the HDMI transmitter amplitude output signal control circuits in Fig. 3.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained every other under the premise of creative work is not made
Embodiment, belong to the scope of protection of the invention.
Fig. 1 is a kind of HDMI transmitters amplitude output signal control circuit disclosed in the embodiment of the present application.
Referring to Fig. 1, the HDMI transmitters amplitude output signal control circuit disclosed in the present application includes：
Decoder 1, voltage detector 2, comparator 3, counter 4 and selector 5；
The decoder 1, for obtaining switching signal, when the switching signal is low level, to the voltage detector
The first control signal is exported, otherwise exports the second control signal；
The voltage detector 2, for when the control signal got by the decoder 1 is the first control signal,
By opening corresponding controlling switch, the voltage difference at RL resistance both ends in HDMI transmitters is detected, when the control got
When signal processed is the second control signal, the voltage difference at RR resistance both ends in the HDMI transmitters is detected, and will obtain
The voltage difference at the RL or RR resistance both ends send to comparator 3；
The comparator 3, for compare RL the or RR resistance both ends got voltage difference and datum it is big
It is small and to counter 4 export comparative result, wherein, the datum can be according to user's request sets itself, it is preferred that this
The span of the datum in application can be in 0.4V between 0.6V；
The counter 4 (can be 6bit counters), for the comparative result control counter according to the comparator 3
Value changes；For example, when the output signal of the comparator 3 is low level signal, the Counter Value of the counter 4 subtracts 1, when
When the output signal of the comparator 3 is high level signal, the Counter Value of the counter 4 adds 1, and the Counter Value is changed into
After preset value (can be 0 or 63), the voltage difference at RL or RR resistance both ends described in this thing and the datum about phase be represented
Keep that Counter Value is constant, and now, the Counter Value of the counter 4 is held essentially constant (certainly Deng, the counter 4
It possibly be present at situation about changing in the range of -1,1)；
Selector 5, by obtain by the output signal that improves the HDMI transmitters amplitude correction value c and it is described based on
The Counter Value that number device 4 exports, when only getting the Counter Value when not getting corrected value c, the counter 4 is sent out
The Counter Value sent is sent to HDMI transmitters so that the HDMI transmitters adjust HDMI transmitters according to the Counter Value
In adjustable current source output current, the amplitude of the output signal of the HDMI transmitters is controlled, when getting the correction
After value c, the selector is sent the corrected value c as output signal to HDMI transmitters so that the HDMI transmitters
According to the output of corrected value c adjustment adjustable current sources, so as to adjust the amplitude of the output signal of the HDMI transmitters.
Referring to the technical scheme in the above embodiments of the present application, when the HDMI transmitters amplitude output signal control circuit
During normal work, the Counter Value is controlled by the voltage difference at the RL or RR resistance both ends and the size of datum
Size, the electric current that adjustable current source in the HDMI transmitters is adjusted by the size of the Counter Value exports, and works as discovery
RL the or RR resistance is disconnected when causing HDMI transmitters amplitude output signal to reduce, and user can be by sending to the selector
Corrected value c mode keeps the HDMI transmitters amplitude output signal.
It is understood that in the above embodiments of the present application, the acquisition modes of the corrected value c have a variety of, it is of course possible to
Be user directly input can also use processing of circuit and obtain, for example, the school in the above embodiments of the present application
Can be exported by adjuster on the occasion of c, i.e. referring to Fig. 2, the HDMI transmitter output signal width in the above embodiments of the present application
Degree control circuit can also include：
The correction that input is connected with the output end of the counter 4, output end is connected with the input of the selector 5
Device 6, when the switching signal for being obtained when decoder 5 is low level and counter 4 Counter Value it is stable when Counter Value a
And/or Counter Value b of the switching signal that obtains of decoder 5 when being high level and during 4 value stabilization of counter of counter, foundation
Preset rules gated counter value a and Counter Value b maximum or average value as corrected value c and are sent to selector.
This is, it is necessary to explanation, the maximum or average value conduct according to preset rules gated counter value a and Counter Value b
Corrected value c is simultaneously sent to the preset rules in selector 5, also refers to select larger in the Counter Value a and b one
The selector 5 is sent to as the corrected value c, or both average value is calculated, using the average value as described in
Corrected value c is sent to the counter 5.
Referring to Fig. 1, the amplitude size of the HDMI transmitters output signal, and in HDMI transmitters described in described Fig. 1
Adjustable current source I2 it is relevant with the size of definite value current source I1 output current, be specially：
TX output amplitudes=RL* (I2+I1)+RR* (I2+I1)；
Wherein, the I2=mux_out<5:0>* step, RL* (I2+I1) be RL resistance both ends voltage difference, the RR*
(I2+I1) it is the voltage difference at the RR resistance both ends, the step is mux_out<5:0>I2 increased values when often increasing by 1, when
When not getting corrected value c, the mux_out<5:0>For the Counter Value of the counter 4, when getting corrected value c,
The mux_out<5:0>It is changed into the corrected value c.When the corrected value c using adjuster 6 is as mux_out<5:0>When, such as
Fruit RL=RR=R (R is resistance RL and resistance RR resistance), after adjuster correction, can finally it cause described
The voltage difference at resistance RR and RL both ends is equal to reference value Vref, then TX output amplitudes=2R (I2+I1), by amplitude correction most
R (I2+I1)=Vref can be ensured eventually, that is, TX output amplitudes=2Vref can be ensured.As shown in figure 3, work as HDMI
When TX is multiple, as long as the resistance RL and resistance RR in each HDMI TX are equal to R, then ensure that each HDMI TX's
Output amplitude is consistent.
It is understood that in the above embodiments of the present application, the number of the corrected value c can be multiple, be obtained when simultaneously
When obtaining multiple corrected value c, the selector 5 can select one of them to go to control the HDMI transmitters according to pre-set priority
In adjustable current source, such as the quantity of the corrected value c in the application can be two, i.e. the first corrected value and the second school
On the occasion of.
It is understood that when the corrected value c includes the first corrected value and the second corrected value, first corrected value
Can be the output signal of above-mentioned adjuster 6, the input of the adjuster 6 is connected with the output end of the counter 4, exported
End is connected with the input of the selector 5, when the switching signal for being obtained when decoder 1 is low level and counter 4
When the switching signal that Counter Value a and/or decoder 1 when Counter Value is stable are obtained is high level and counter 4 counting
Counter Value b during device value stabilization, maximum or average value according to preset rules gated counter value a and Counter Value b are made
Sent for the first corrected value path2 to selector；
The second corrected value path2 is the adjustable corrected value of user's input, it is to be understood that second correction
Value path2 can be the corrected value that user is write by software.Wherein, the priority of the second corrected value path2 can be high
In the first corrected value path2 priority.
It is understood that in the above embodiments of the present application, the voltage detector 2 can be any one in the prior art
Kind is capable of the circuit or equipment of the voltage difference at detection resistance both ends, and for example, with reference to Fig. 2, the voltage detector 2 can be subtraction
Device；
The ungrounded end that the positive input terminal of the subtracter passes through RL resistance in the first controlling switch SW1 and HDMI transmitters
It is connected, is connected by the 3rd controlling switch SW3 with the ungrounded end of RR resistance in HDMI transmitters；
The ungrounded end that the negative input end of the subtracter passes through RL resistance in the second controlling switch SW2 and HDMI transmitters
It is connected, is connected by the 4th controlling switch SW4 with the ungrounded end of RR resistance in HDMI transmitters；
Now, the decoder 1, also particularly useful for when the switching signal is low level, exported to the subtracter
For control described first and the 4th controlling switch disconnect, second and the 3rd controlling switch closure the first control signal, otherwise
Export the second control signal disconnected for the controlling switch of the first and the 4th controlling switch of control closure, second and the 3rd.
It is understood that in the above embodiments of the present application, the specific connected mode of the comparator 3 can be：It is described
The in-phase input end of comparator 3 is used to obtain reference level Vref, and inverting input is used for the RL for obtaining the detector output
Or the voltage difference Vdiff at RR resistance both ends, output end are connected with the input of the counter 4.
It is understood that referring to Fig. 2, disclosed herein as well is a kind of concrete structure of the adjuster 6, including；
The first latch 601 and the second latch 602 that first input end is connected with the output end of the counter 4；
First input end is connected with the output end of first latch 601, the second input and second latch
The processor 603 that 602 output end is connected, output end is connected with the input of the selector 5；
Second input of first latch 601 obtains the first latch signal load；
Second input of second latch 602 obtains the second latch signal load_inv；
First latch 601 is used for when the first latch signal load got is high level, latches this
The Counter Value of Shi Suoshu counters 4, and latch result is sent to the processor 603；
Second latch 602 is used for when the second latch signal load_inv got is high level, lock
The Counter Value of the now counter 4 is deposited, and latch result is sent to the processor 603；
The processor 603 is used to calculate the latch result that the latch 603 of the first latch 601 and second is sent
Maximum and average value, and input the maximum or average value to selector 5 according to preset rules；
Wherein, the first latch signal load and the second latch signal load_inv can be by clock-signal generator controls
System is after adjuster startup, to the first latch signal load and the second latch signal load_inv output high level pulse letters
Number time be controlled, can also generate high level pulse under given conditions certainly, the specified conditions refer to：Switching signal
For low level when and counter 4 Counter Value it is stable when, the first latch signal load exports high level pulse signal, when
When switching signal is high level and counter 4 Counter Value it is stable when, the high electricity of the second latch signal load_inv outputs
Flat pulse signal, when being controlled by the clock-signal generator：The clock-signal generator the adjuster work after,
When switching signal is low level, the first latch signal output high level pulse signal is controlled after being spaced preset time period, when
When switching signal is high level, the first latch signal output high level pulse signal is controlled after being spaced preset time period, its
In, the prefixed time interval is the time interval that the counter 4 is changed to by after stabilization, and applicant sends out through research
Existing, the period of change of the time interval is substantially stationary, and therefore, user can be by controlling clock-signal generator judging to switch
Control the first latch signal load or the second latch signal load_inv defeated after the current state of level, after preset time period
Go out the set-up mode of high level pulse signal, control the latch 602 of the first latch 601 and second to perform latching action,
Without judging whether the counter 4 reaches stable state.
It is understood that the selector 5 in the above embodiments of the present application can be any one tool in the prior art
Have the selector of signal behavior and output function, for example, when the selector 5 need two input ports (Counter Value
The input port of input port and corrected value) when, it can be made up of a data selector, and the of the data selector
One input is connected with the output end of the counter 4, the second input is connected with the output end of the adjuster 6.Such as Fig. 2 institutes
Show, when the selector 5 is needed with (input port, the first corrected value and the second correction of Counter Value of three input ports
The input port of value) when, the selector 5 can be made up of two data selectors, i.e. the first data selector 501 and second
Data selector 502, as shown in Fig. 2 the output of the first input end of first data selector 501 and the counter 4
End is connected, the second input is connected with the output end of the adjuster 6；The first input end of second data selector 502 and institute
The output end for stating the first data selector 501 is connected, the second input is used to obtain the second corrected value path3, second number
According to output end of the output end of selector 502 as the selector.
It is understood that using HDMI transmitters amplitude output signal control circuit disclosed in the above embodiments of the present application
It can also realize while the amplitude of the output signal of multiple HDMI transmitters is controlled, as shown in Figure 3 and Figure 4, wherein, institute
The structure chart that Fig. 3 is the HDMI transmitter amplitude output signal control circuits that the present embodiment provides is stated, described Fig. 4 is that the application is real
The control sequential change schematic diagram of the control signal in example is applied, is carried out when needing the amplitude to the output signal of NHDMI transmitters
During control, the number of the adjuster 6 and selector 5 is N number of, and the adjuster is corresponded with selector and is connected, often
One selector corresponds to only one HDMI transmitters, and the adjuster 6 includes first selector 601 and second selector 602；
Now the decoder 1 also obtains period 1 signal hdmi_cal_path_sel<1:0>, it is described referring to Fig. 3
Period 1 signal hdmi_cal_path_sel<1:0>For periodic signal, the switching signal cal_inv is detected for working as
For low level when, in the period 1 signal hdmi_cal_path_sel<1:0>First complete cycle in control described in
Voltage detecting circuit 2 is connected with the first HDMI transmitters, detects the voltage difference at the RL resistance both ends of the first HDMI transmitters, is working as
Preceding hdmi_cal_path_sel<1:0>Cycle after the dly0 times, controls the school to match with the first HDMI transmitters
First latch signal load of positive device 6<0>High level pulse is exported, controls the latch in the adjuster 6 to perform latching action,
Next hdmi_cal_path_sel<1:0>The control voltage detecting circuit 2 is connected with next HDMI transmitters in cycle, examines
The voltage difference at the RL resistance both ends of next HDMI transmitters is surveyed, in current hdmi_cal_path_sel<1:0>Cycle passes through dly0
After time, the first latch signal load of the adjuster 6 that control matches with the described HDMI transmitters<1>Export high level arteries and veins
Punching, the latch in the adjuster 6 is controlled to perform latching action, the rest may be inferred, to the last corresponding to a HDMI transmitter
First latch signal load of adjuster 6<3>After exporting high level pulse, the latch in the adjuster 6 is controlled to perform latch
Untill action；When it is high level to detect the switching signal cal_inv, in the period 1 signal hdmi_cal_
path_sel<1:0>First complete cycle in the control voltage detecting circuit 2 be connected with the first HDMI transmitters, detection
The RR resistance both end voltages of the first HDMI transmitters are poor, in current hdmi_cal_path_sel<1:0>Cycle passes through dly0
After time, the second latch signal load_inv of the adjuster 6 that control matches with the first HDMI transmitters<0>Output is high
Level pulse, the latch in the adjuster 6 is controlled to perform latching action, next hdmi_cal_path_sel<1:0>In cycle
Control the voltage detecting circuit 2 with the first HDMI transmitters to be connected with next HDMI transmitters to be connected, detect next HDMI hairs
The voltage difference at emitter RR resistance both ends, in current hdmi_cal_path_sel<1:0>Cycle after the dly0 times, control with
Second latch signal load_inv of the adjuster 6 that the described HDMI transmitters match<1>High level pulse is exported, control should
Latch in adjuster 6 performs latching action, and to the last second of adjuster 6 corresponding to a HDMI transmitter latches letter
Number load_inv<3>After exporting high level pulse, untill controlling the latch execution latching action in the adjuster 6.
It is understood that applicant is also to this intuitively to be understood to the control signal in Fig. 4 in order to more convenient
Figure is explained, and in Fig. 4, the number of the HDMI transmitters, selector and adjuster is 4：
Rst_n is low level reset signal, and rg_hdmi_cal_en is adjuster enabling signal, and high level starts correction
Device, low level close adjuster, and the rg_hdmi_cal_en can be high or low by software design patterns.Hpd is that hdmi heat is inserted
Detection signal is pulled out, high level represents to plug, and low level represents not plug.Hdmi_vsense represents detection HDMI transmitter outputs
End is either with or without RL and RR (50 Ω) is connected, if connected, hdmi_vsense is high level, is not connected as low level.Work as rst_
When n is high level, rg_hdmi_cal_en=1, hpd=1, hdmi_vsense=1, pulse1 signals are produced by hardware, accused
Know that correction signal is ready for, produce delay pulse2 signals (1ms, can be by software design patterns time delay), delay
The pulse3 signals system of informing is produced after end can produce da_hdmi_cal_en signals, and da_hdmi_cal_en is high electricity
After flat, the circuit starts to perform corrective action.As period 1 signal hdmi_cal_path_sel<1:0>Selected during=2 ' b00
0 channel correcting, the load after the dly0 times<0>Signal output high level pulse, the Counter Value of this hour counter is latched
Get up；hdmi_cal_path_sel<1:0>=2 ' b01 select 1 channel correcting, the load after the dly0 times<1>Signal output
High level pulse, control the latch in adjuster that the Counter Value of this hour counter is latched；hdmi_cal_path_
sel<1:0>=2 ' b10 select 2 channel correctings, the load after the dly0 times<2>Signal output high level pulse signal, control
Latch in adjuster latches the Counter Value of nonce counter get up；hdmi_cal_path_sel<1:0>=2 ' b11
3 channel correctings are selected, the load after the dly0 times<3>Signal output high level pulse signal, control the latch in adjuster
Device latches the Counter Value of nonce counter get up.After cal_inv is changed into high level, represents that both positive and negative polarity will exchange and do school
Just, hdmi_cal_path_sel<1:0>=2 ' b00 select 0 channel correcting, the load_inv after the dly0 times<0>Signal is defeated
Go out high level pulse signal, control the latch in adjuster that the Counter Value of nonce counter is latched；hdmi_cal_
path_sel<1:0>=2 ' b01 select 1 channel correcting, after the dly0 times, load_inv<1>Signal output high level arteries and veins
Signal is rushed, controls the latch in adjuster that the Counter Value of nonce counter is latched；hdmi_cal_path_sel<
1:0>=2 ' b10 select 2 channel correctings, after the dly0 times, load_inv<2>Signal output high level pulse signal, control
Latch in adjuster processed latches the Counter Value of nonce counter get up；hdmi_cal_path_sel<1:0>=2 '
B11 selects 3 channel correctings, after the dly0 times, load_inv<3>Signal output high level pulse signal, control adjuster
In latch the Counter Value of nonce counter is latched, now trimming process has terminated, and Cal_mux_sel is changed into high
Level, da_hdmi_cal_en are changed into low level, allow maximum that adjuster calculates or average value control HDMI TX
Output current.If Plug Action will then repeat said process.
It is understood that each level signal in the above embodiments of the present application can be occurred by pulse signal
Device generates, and the pulse signal generator controls mechanical periodicity and the low and high level change of each signal according to preset rules.
Each embodiment is described by the way of progressive in this specification, what each embodiment stressed be and other
The difference of embodiment, between each embodiment identical similar portion mutually referring to.
The foregoing description of the disclosed embodiments, professional and technical personnel in the field are enable to realize or using the present invention.
A variety of modifications to these embodiments will be apparent for those skilled in the art, as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, it is of the invention
The embodiments shown herein is not intended to be limited to, and is to fit to and principles disclosed herein and features of novelty phase one
The most wide scope caused.
Claims (10)
- A kind of 1. HDMI transmitters amplitude output signal control circuit, it is characterised in that including：The voltage detector that input is connected with HDMI transmitters；For controlling the connection between the HDMI transmitters and the voltage detector according to the switch level signal got The decoder of relation；The decoder, it is used to control the voltage detecting for when the switching signal is low level, exporting First control signal of the voltage difference at RL resistance both ends in device detection HDMI transmitters, when the switching signal is high level, Export the second control signal for controlling the voltage difference at RR resistance both ends in the voltage detector detection HDMI transmitters；In-phase input end is used to obtain datum, the comparison that inverting input is connected with the voltage detecting circuit output end Device；The counter that In inputs are connected with the output end of the comparator；First input end is connected with the output end of the counter, the second input be used for obtain corrected value c, output end with it is described The connected selector of HDMI transmitters；The selector, for when not getting corrected value c, the Counter Value that the counter is sent being sent to HDMI and sent out Emitter so that the output of the HDMI transmitters according to Counter Value adjustment adjustable current source, when getting the corrected value c When, the corrected value c is sent to HDMI transmitters so that the HDMI transmitters are according to corrected value c adjustment adjustable current sources Output.
- 2. HDMI transmitters amplitude output signal control circuit according to claim 1, it is characterised in that also include：First input end is connected with the output end of the counter, the second input is used to obtain latch signal, output end and institute The connected adjuster of the input of selector is stated, for when the latch signal got is high level pulse signal, latching and working as Preceding Counter Value, sent the Counter Value deposited as corrected value c to the selector；Wherein, when the switching signal is low level and counter Counter Value it is stable when, the latch signal is high electricity Flat pulse signal；When switching signal is high level and counter Counter Value it is stable when the latch signal be high level pulse Signal.
- 3. HDMI transmitters amplitude output signal control circuit according to claim 1, it is characterised in that the corrected value C includes the first corrected value and the second corrected value；The selector also includes correction value selector, for selecting first corrected value or the second school according to pre-set priority On the occasion of as the corrected value c.
- 4. HDMI transmitters amplitude output signal control circuit according to claim 3, it is characterised in that first school On the occasion of the output signal for adjuster；The first input end of the adjuster is connected with the output end of the counter, the second input is used to obtain latch letter Number, output end be connected with the input of the selector, for when the latch signal got is high level pulse signal, lock Present counter value is deposited, is sent the Counter Value deposited as corrected value c to the selector；Wherein, when the switching signal is low level and counter Counter Value it is stable when, the latch signal is high electricity Flat pulse signal；When switching signal is high level and counter Counter Value it is stable when the latch signal be high level pulse Signal；Second corrected value is the adjustable corrected value of user's input.
- 5. HDMI transmitters amplitude output signal control circuit according to claim 4, it is characterised in that second school On the occasion of priority be more than the first corrected value priority.
- 6. the HDMI transmitter amplitude output signal control circuits according to claim 1-5 any one, it is characterised in that The voltage detector is subtracter；The positive input terminal of the subtracter is connected with the ungrounded end of RL resistance in HDMI transmitters by the first controlling switch, is logical The ungrounded end that the 3rd controlling switch is crossed with RR resistance in HDMI transmitters is connected；The negative input end of the subtracter is connected with the ungrounded end of RL resistance in HDMI transmitters by the second controlling switch, is logical The ungrounded end that the 4th controlling switch is crossed with RR resistance in HDMI transmitters is connected.
- 7. HDMI transmitters amplitude output signal control circuit according to claim 6, it is characterised in that：The decoder, specifically for obtaining switching signal, when the switching signal is low level, export for controlling described the First control signal of the controlling switch closure of the disconnection of the one and the 4th controlling switch, second and the 3rd；When the switching signal is height During level, the second control letter disconnected for the controlling switch of the first and the 4th controlling switch of control closure, second and the 3rd is exported Number.
- 8. the HDMI transmitter amplitude output signal control circuits according to claim 2 or 4, it is characterised in that the school Positive device includes；The first latch and the second latch that first input end is connected with the output end of the counter；First input end is connected with the output end of first latch, the output end of the second input and second latch It is connected, the processor that output end is connected with the input of the selector；Second input of first latch obtains the first latch signal；Second input of second latch obtains the second latch signal；First latch is used for when first latch signal got is high level pulse signal, latches now institute The Counter Value of counter is stated, and latch result is sent to the processor；Second latch is used for when second latch signal got is high level pulse signal, latches now institute The Counter Value of counter is stated, and latch result is sent to the processor；The processor is used for the maximum for calculating the latch result that first latch and the second latch are sent and is averaged Value, and input the maximum or average value to selector according to preset rules；Wherein, first latch signal, wherein first latch signal is when the switching signal is low level and counting The Counter Value of device is high level pulse signal when stable；Second latch signal when the switching signal is high level and The Counter Value of counter is high level pulse signal when stable.
- 9. HDMI transmitters amplitude output signal control circuit according to claim 4, it is characterised in that the selector Including：First input end is connected with the output end of the counter, the second input is connected with the output end of the adjuster One data selector；First input end is connected with the output end of first data selector, the second input is used to obtain the second corrected value Second data selector, the output end and HDMI transmitter phases of the output end of second data selector as the selector Even.
- 10. HDMI transmitters amplitude output signal control circuit according to claim 4, it is characterised in that including：The number of the adjuster and selector is N number of, and the adjuster is corresponded with selector and is connected, each selection The corresponding HDMI transmitters of device；The decoder is additionally operable to obtain period 1 signal, for when it is low level to detect the switching signal, in institute Exported during first complete cycle for stating period 1 signal for controlling the voltage detecting circuit to detect the first HDMI transmittings The control signal of the voltage difference at the RL resistance both ends of device, export during next cycle for controlling under the voltage detecting circuit detects The control signal of the voltage difference at the RL resistance both ends of one HDMI transmitters；When it is high level to detect the switching signal, Exported during first complete cycle of the period 1 signal for controlling the voltage detecting circuit to detect the first HDMI hairs The control signal of the voltage difference at the RR resistance both ends of emitter, export during next cycle for controlling the voltage detecting circuit to detect The control signal of the voltage difference at the RR resistance both ends of next HDMI transmitters.
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| CN201510175239.7A CN104811644B (en) | 2015-04-14 | 2015-04-14 | A kind of HDMI transmitters amplitude output signal control circuit |
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| CN105680841B (en) * | 2015-12-29 | 2018-05-08 | 龙迅半导体（合肥）股份有限公司 | Switch module and its control method |
| CN110493634B (en) * | 2019-07-04 | 2021-07-27 | 北京雷石天地电子技术有限公司 | Method and system for volume control |
| CN113572484B (en) * | 2020-04-28 | 2022-06-21 | 瑞昱半导体股份有限公司 | Emitter device and correction method |
| CN114780477B (en) * | 2022-06-22 | 2022-10-04 | 龙迅半导体（合肥）股份有限公司 | TYPE-C configuration channel receiver, data processing method and electronic equipment |
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