| ??? 06/13/07 13:09 Modified: 06/13/07 13:13 Read: times |
#140663 - hummm.... Responding to: ???'s previous message |
Bryan Randall said:
[...]the strange thing is that the parts of our code that do not work when running from FLASH are using an external serial port that is bus connected on another board.[...] The only difference between a '51 running from internal code memory compared to external code memory is, that during execution from internal code memory it stops issuing pulses on /PSEN and won't emit the "proper" address onto P0/P2. The 'V51RD2 also has an ALE disable SFR bit, but I doubt you set it in the "old hex" (and it is by default off). So, your problem must be related somehow to the "not-changing-often-enough" P0/P2/PSEN. Any chance posting the schematics here? JW PS. Bryan, have you tried to run from the external memory with the SAME 'V51RD2 AFTER having unsuccessfully run it from internal memory? (I won't tell you why I am asking until you won't answer me this question - or guess yourself :-) ) |
| Topic | Author | Date |
| 89V51 Code running from FLASH vs EPROM | 01/01/70 00:00 | |
| faulty code | 01/01/70 00:00 | |
| timing? | 01/01/70 00:00 | |
| I need some shematics and programe code using asm | 01/01/70 00:00 | |
| 89V51 Code running from FLASH vs EPROM | 01/01/70 00:00 | |
| hummm.... | 01/01/70 00:00 | |
| OK, We're on to something.... | 01/01/70 00:00 | |
| questions | 01/01/70 00:00 | |
| OK, then don't switch on the /2 flag! | 01/01/70 00:00 | |
| /2 Flag | 01/01/70 00:00 | |
| and the code security flag? | 01/01/70 00:00 | |
| PLM51 Question. | 01/01/70 00:00 | |
| TWO WRONGS | 01/01/70 00:00 | |
| I am still not convinced... | 01/01/70 00:00 | |
| Still a Problem, but........ | 01/01/70 00:00 | |
| P89v51 does have some differences | 01/01/70 00:00 | |
had to wait 5 minutes on someone | 01/01/70 00:00 |