| ??? 12/20/07 14:34 Read: times |
#148547 - clock and ALE Responding to: ???'s previous message |
1)where is connected ALE?
2)"HC139 and HC573 are used as address decoding and chip selection... " - is this related to EPROM and how? 2)CPU crystal 20MHz means access time <50nsec - see figure 19 document doc4129.pdf from Atmel . And Your EPROM is 90nsec. Try with 5..7MHz crystal. regards |
| Topic | Author | Date |
| T89C51CC01UA not run on external code mem | 01/01/70 00:00 | |
| T89C51CC01UA not run on external code memory (2) | 01/01/70 00:00 | |
| I see no mention of !EA | 01/01/70 00:00 | |
| Re: I see no mention of !EA | 01/01/70 00:00 | |
| clock and ALE | 01/01/70 00:00 | |
| Re: clock and ALE | 01/01/70 00:00 | |
| Re: clock and ALE | 01/01/70 00:00 | |
| hardware security byte | 01/01/70 00:00 | |
| not an admonsihment, just a thought | 01/01/70 00:00 | |
Re: hardware security byte | 01/01/70 00:00 | |
| T89C51CC01UA not run on external code mem | 01/01/70 00:00 |