Earliest data output time considering TACC in 8085 Microprocessor


27128 receives the Address A13-8 by 27128 from 8085AH by means of the octal line driver 74LS244, which has a propagation delay of 12 nS. Address ranging from A7-0 is received by 27128 from 8085AH by means of 74LS373 octal latch, which consists of a propagation delay of 30 nS. Thus, address ranging from A13-0 is received by 27128 at the end of 30 nS. So the data only comes out on D7-0 pins of 27128 by 30 nS + tAcc = 30 nS + 200 nS = 230 nS.

  Delays involved in accessing 27128 EPROM in ALS kit.

 Bus timing characteristics of MR machine cycle

Published on 13-Mar-2019 13:03:30