| ??? 09/29/05 18:06 Read: times |
#101738 - if you are ANDing them it will never wor Responding to: ???'s previous message |
By AND'ing PSEN and RD produces a low output on any read, code memory or data memory. This low enables the '245 DIR pin for a read process to the CPU
if you are ANDing them it will never work; however, if you are negative ORing them it may. is the 'a' or 'b' side of the 245 facing the uC? Erik |
| Topic | Author | Date |
| Buffering address/data bus Basic-52 | 01/01/70 00:00 | |
| direction | 01/01/70 00:00 | |
| Yes | 01/01/70 00:00 | |
| '573? | 01/01/70 00:00 | |
| 245 | 01/01/70 00:00 | |
| Only need one latch | 01/01/70 00:00 | |
| Re-read this... | 01/01/70 00:00 | |
| negative logic | 01/01/70 00:00 | |
| caqll a spade a spade | 01/01/70 00:00 | |
| Ok... I follow you, but... | 01/01/70 00:00 | |
| 74F623 instead of 74F245 | 01/01/70 00:00 | |
| I'd stick with a 245 | 01/01/70 00:00 | |
74AC623 is also fast | 01/01/70 00:00 | |
| A little clarification | 01/01/70 00:00 | |
| if you are ANDing them it will never wor | 01/01/70 00:00 | |
| How fast is your memory? | 01/01/70 00:00 |