JPS57189236A - Information reading system - Google Patents

Abstract

PURPOSE:To enable reading of huge counting values with simple constitution, by selecting the output of n sets of registers in cascade connection at n bits of a register of n+1 bits, outputting the result to a common bus and writing it at the n+1-th bit. CONSTITUTION:Outputs of n sets of registers 11-1n in cascade connection are connected to a common bus 14. A pulse is sequentially given to a shift input T of an n+1-bit counter 21 every time an output request signal R is given, selection signals S1-Sn are applied from the outputs of the 1st-n-th bits and the counting values of the corresponding registers 11-1n are transmitted to the bus 14. During this operation, the (n+1)-th bit output signal Q of the counter 21 is 0 and the reception of a succeeding input pulse Pin is inhibited by an AND gate. When all data of the registers 11-1n are picked up, the signal Q is switched to 1 by an EOR gate 22 and the next input pulse Pin is read to the registers 11-1n sequentially.