| ??? 12/27/04 17:08 Read: times |
#83950 - Caught the cause of problem. Responding to: ???'s previous message |
Dear Erik,
Thanks a lot for your reply. Yes it is EXTRAM bit in AUXR register that might be causing problem. With P89V51RD2 it is clear upon reset. Thus the internal XRAM is enabled. But with P89C668 the reset status of EXTRAM is set and internal XRAM is not accessed with MOVX instructions. And to use internal XRAM of P89C668 user program must clear EXTRAM bit. I will try the code tomorrow with '668 and let you know the results. 2) the '668 is switched between 6 and 12 clock by a fuse which can only be changed by parallel programming. The V can be changed by ISP. Virgin P89V51RD2 comes in 12 clock mode and can be changed to 6 clock moe using ISP but once changed to 6 clock mode it can't be brought back to 12 clock mode using ISP. You need parallel programmer for reverting back to 12clock. Thanks & Regards, Prahlad Purohit. |
| Topic | Author | Date |
| P89C668 MOVC problem. | 01/01/70 00:00 | |
| Earlier discussions. | 01/01/70 00:00 | |
| Timing problem? | 01/01/70 00:00 | |
| Re: Timing Problem. | 01/01/70 00:00 | |
| How do you program? | 01/01/70 00:00 | |
| Seciurity bits. | 01/01/70 00:00 | |
| A bug in the chip? | 01/01/70 00:00 | |
| Can you give the schematic ? | 01/01/70 00:00 | |
| Schematic is here. | 01/01/70 00:00 | |
| Real code I will post tomorrow. | 01/01/70 00:00 | |
| More sacrifice needed | 01/01/70 00:00 | |
| Flash Magic | 01/01/70 00:00 | |
| Flash Magic | 01/01/70 00:00 | |
| XRAM Turn ON. | 01/01/70 00:00 | |
| I missed this - Russell. | 01/01/70 00:00 | |
| maybe | 01/01/70 00:00 | |
| Caught the cause of problem. | 01/01/70 00:00 | |
256 bytes less... | 01/01/70 00:00 |