| ??? 04/16/07 13:09 Modified: 04/16/07 14:57 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#137322 - One further comment is needed Responding to: ???'s previous message |
Patrick said:
no further comments are needed. One further comment is needed: The idea tha RET returns to an address that's stored in a pair of registers is pointless and confusing. This idea has already resulted in references to R8 and R9, which don't even exist! This idea first came up in Mike's discussion of an incorrect program where the RET was executed without first executing an ACALL or LCALL instruction. In every normal case, RET will return to an address that was pushed onto the stack by a corresponding ACALL or LCALL. By the time the RET instruction is executed, the stack pointer will be above any registers that are being used, at an address that is of no consequence as long as the stack doesn't overflow. So don't start thinking that RET returns to an address stored in the registers. In every normal case, it doesn't. -- Russ |
| Topic | Author | Date |
| RxD to LCD problems | 01/01/70 00:00 | |
| Serial ISR | 01/01/70 00:00 | |
| work needed. | 01/01/70 00:00 | |
| you need to control flow | 01/01/70 00:00 | |
| confused | 01/01/70 00:00 | |
| this is what I mean | 01/01/70 00:00 | |
| OK | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| Non-useful Serial ISR | 01/01/70 00:00 | |
| AND it's stuck | 01/01/70 00:00 | |
| thanks | 01/01/70 00:00 | |
| I was going for optimization. | 01/01/70 00:00 | |
| It's functioning | 01/01/70 00:00 | |
| now stay consistent | 01/01/70 00:00 | |
| Terminating code? | 01/01/70 00:00 | |
| . | 01/01/70 00:00 | |
| correct terminology | 01/01/70 00:00 | |
| Missing the point | 01/01/70 00:00 | |
| i get it now | 01/01/70 00:00 | |
| Most, but not all | 01/01/70 00:00 | |
| why on earth | 01/01/70 00:00 | |
| if it\'s almost correct, it\'s still wrong :-) | 01/01/70 00:00 | |
| ok | 01/01/70 00:00 | |
| Not R6 and R7 | 01/01/70 00:00 | |
| well it happend again | 01/01/70 00:00 | |
| Q.E.D. | 01/01/70 00:00 | |
| One further comment is needed | 01/01/70 00:00 | |
| Hey | 01/01/70 00:00 | |
| Dangerous recommendation | 01/01/70 00:00 | |
| good point | 01/01/70 00:00 | |
they all do | 01/01/70 00:00 | |
| it 'trust' the same as 'experiment'? | 01/01/70 00:00 | |
| more issues | 01/01/70 00:00 | |
| Joe, please read this | 01/01/70 00:00 |