| ??? 01/04/08 17:19 Read: times |
#149051 - P89V51 firmware upgrade Responding to: ???'s previous message |
Hello Jan,
Jan Waclawek said:
Your description is roughly right, although in some details it's imprecise... For example, there is no need to rewrite the longjump instruction in the FLASH, in fact; there are 3 zeros written to the first 3 positions "manually" - no jump existed there previously, the whole sector was erased. If the 1st 8 Ko of the block0 (user) is erased, how can the block1 be updated ? I think the 1st 8Ko of the block0 must be copied in the block1 before being erased. This part of the firmware looks a little "tricky" for me! For the "register" at address 21H, you 're right: it's the 1st bit addressable byte of the internal RAM, not a SFR. The disassembled line is: clr 21h.0 I think the bit0 of this byte is used as a flag in the firmware, but I did not found its meaning (at this time). Regards, Phil. |
| Topic | Author | Date |
| P89V51RC2_V03_UPD_ISP.HEX Question | 01/01/70 00:00 | |
| yes, this is an _upgrader_ | 01/01/70 00:00 | |
| Flash Mapping in P89v51 | 01/01/70 00:00 | |
| P89V firmware update: to be continue... | 01/01/70 00:00 | |
| that's no shame | 01/01/70 00:00 | |
| P89V51 firmware upgrade | 01/01/70 00:00 | |
| it goes like this: | 01/01/70 00:00 | |
Thanks | 01/01/70 00:00 |