JPS62123521A - Buffer memory control system for floppy disk device - Google Patents

Abstract

PURPOSE:To make a CPU carry out other processing jobs continuously even in a transfer mode of the data on a floppy disk FD, by using an exclusive direct memory access device DMA and a buffer memory for transfer of the data on the FD. CONSTITUTION:When data are loaded to a buffer memory 18 from an FD10, an FD controller 11 delivers a DMA request signal DRQ to a DMA12. While the DMA12 sends a DMA permission signal DACK back to the controller 11 and starts the transfer of data to load them into the memory 18. A CPU 13 can read the contents of the memory 18 via a local data bus 17 after the data are loaded to the memory 18 because the memory 18 has a duel port constitution.

Description

[Detailed description of the invention] [Industrial application field] What is the invention? -Used in internal computers, etc.
The present invention relates to a control method for a floppy disk device that transfers data between the floppy disk device and a memory using a memory direct access method.

[Conventional technology]

Conventionally, in data transfer between a floppy disk device and a main memory (MM), as shown in FIG. ') and memory direct access device 12
issues a bus usage right acquisition request (IRQ) to the central processing unit CPU 13. Next, CPU 13 uses DMA 1
Return permission (HACK) to use the bus to 2, DMA
12 is a DM for the floppy disk control device 11.
The process was such that data transfer was performed after A permission (DACK) was returned.

Note that the CPU 13 and main memory 14 are connected to an address bus (A
-BUS) 15, data bus (D-BUS) 16
are respectively connected to the floppy disk control device 11.
hr-p bus 16: and DMA 12id address bus 15, respectively.

[Problem that the invention seeks to solve]

The above-mentioned conventional floppy disk device lu: Data transfer with the main memory 14 by the DMA 12 is performed by the CPU 1.
3 temporarily transfers the right to use the bus to the DMA 12, the data on the floppy disk is transferred to the main memory 1.
4, the CPU 13 is in a sleep state,
The drawback is that the CPU 13 cannot perform other processing.

[Means for solving problems]

The buffer memory control method of the floppy disk device of this invention uses a D
A MA and a buffer memory with a dual port configuration are provided, and the buffer memory, floppy disk device, and data bus are connected to a local data bus, and a memory direct access device (DMA) is used to connect the floppy disk device control device and the buffer memory. Data transfer is performed via the local data bus. Therefore, during this data transfer, there is no need to pass the right to use the data bus connected to the central processing unit to the memory direct access device, and the central processing unit can perform other processing. Note that the contents of the central processing unit's buffer memory can be read via the data bus.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and parts corresponding to those in FIG. 2 are given the same reference numerals. The CPU 13 further connects to a local data bus (LD-B) via a data bus 16.
It is also connected to a buffer memory (BM) 18 having a dual port configuration through the US) 17 &. The address bus 15 and the address lines of the DMA 12 are connected to a buffer memory 18 via a multiplexer 19. On the other hand, the floppy disk device 10 is connected to a buffer memory 18 via a floppy disk controller 11 and a local data bus 17.

When loading data from the floppy disk device 10 into the buffer memory 18, the system performs the following operations.

(1) The floppy disk control device 11 is a DMA 12
A DMA request signal (DRQ) is issued to the

(2) The DMA 12 returns a DMA permission signal (DACK) to the floppy disk controller 11, starts data transfer, and loads the data into the buffer memory 18.

Since the buffer memory 18 has a dual port configuration, the CPU 13 can read the contents of the buffer memory 18 via the data bus 17 after loading data into the buffer memory 18 .

〔Effect of the invention〕

As explained above, this invention has a dedicated DMA and buffer memory for floppy disk data transfer, so there is no need to pass the right to use the path to the DMA even while floppy disk data is being transferred, and the CPU can be paused. This has the effect of allowing other processing to be executed without any processing.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a buffer memory control method for a floppy disk device according to the present invention, and FIG. 2 is a block diagram showing a conventional floppy disk device control method. 10: Floppy disk device, 11: Floppy disk control device, 12: Memory direct access device (D
MA), 13: Central processing unit (CPU), 14: Main memory, 15 Near address bus, 16: Data bus, 17
: Local data bus, 18: Buffer memory, 19:
multiplexer.

Claims (1)

[Claims] (1) A memory direct access device dedicated to controlling the floppy disk device, a buffer memory that can be accessed from either the address from the memory direct access device or the address of the central processing unit, and the buffer memory and the central processing unit described above. a data bus connected to the floppy disk device, and a local data bus connected to a control device of the floppy disk device, and the memory direct access device connects the floppy disk device and the buffer memory through the local data bus. A buffer memory control method for floppy disk devices that enables data transfer.