| ??? 01/20/06 15:46 Read: times |
#107893 - direct movx Responding to: ???'s previous message |
OP (loosely) said: Is there an instruction to move accumulator into code memory? me said: No there is not. However, some of the newer FLASH-based 8051 derivatives are able to write "themselves", although it is never such straighforward as using a single instruction Erik Malund said:
some (all I know) SILabs derivatives have a flag that state "direct movx to the flash" Yes it is prinicpially possible, and it is not too different from writing the address and data into special* SFRs - although IAP always has some gotchas - you need to run in a different part of flash (in some cases read: from bootROM), or the processor might stop for the time the write actually happens - all of that is possible and depends on how IAP on particular derivative is implemented. We just can argue on the wording (which itself has no meaning), whether the OP meant a special type of instruction such as SPM in AVRs or just a standard '51 instruction in some special context (based on bits in SFRs). My final word is, still: IAP is possible 1.only on certain derivatives, and 2. the procedure is implementation dependent. Jan Waclawek * a linguistic nonsense, special special function register :-) |
| Topic | Author | Date |
| event logging | 01/01/70 00:00 | |
| How do you want to do it? | 01/01/70 00:00 | |
| instruction | 01/01/70 00:00 | |
| Read this! | 01/01/70 00:00 | |
| write to code memory | 01/01/70 00:00 | |
| not always true | 01/01/70 00:00 | |
| direct movx | 01/01/70 00:00 | |
| where dpes IAP come in????? | 01/01/70 00:00 | |
| and what? | 01/01/70 00:00 | |
| event logging is storing data, not instr | 01/01/70 00:00 | |
| it's just a label | 01/01/70 00:00 | |
| writing those have nothing, nada, zero | 01/01/70 00:00 | |
| sure | 01/01/70 00:00 | |
| to store into code memory | 01/01/70 00:00 | |
| PLS HELP | 01/01/70 00:00 | |
| My Suggestion... | 01/01/70 00:00 | |
| Don't shout! | 01/01/70 00:00 | |
| pls help | 01/01/70 00:00 | |
| define | 01/01/70 00:00 | |
Thanks | 01/01/70 00:00 |