| ??? 03/08/05 21:48 Read: times |
#89301 - On jokes, reasons &al. Responding to: ???'s previous message |
Sorry, Piter, I don't understand your joke - can you please explain it for me? --- As for reasons, why investigate nonsense instructions, undocumented features? Except I found this funny, this unveils a little the internals of the '51 core. This may sound of little use for everyday '51 practice, hw and sw. But - for somebody, who designs a '51 softcore, this may be a useful bit of information. A more "normal" use of this knowledge (together with similar "deviations") could be a method for distinguishing '51 clones by software - it can use some specific SFR on one of them, perhaps located elsewhere on the other. This is not an esotheric, but a real problem - when playing with the Basic52 on RD2s, I came across a similar problem - how to detect which type of RD2 is present to enable the maximum available XRAM. Similarly, if I would modify it to accept P89V51RD2, I need to cope with the method of IAP invocation different from other RD2s - and now I know, how to distinguish the "V". Of course, one can admit that I should not use undocumented features - true, but I consider B52/RD2 a toy; and perhaps we can get an insider's word on the topic here? Jan Waclawek |
| Topic | Author | Date |
| PUSH SP | 01/01/70 00:00 | |
| 8 | 01/01/70 00:00 | |
| 8??????????????????????????????????? | 01/01/70 00:00 | |
| On jokes, reasons &al. | 01/01/70 00:00 | |
| no, you don't | 01/01/70 00:00 | |
| I do not know and do not think I should | 01/01/70 00:00 | |
| Non-compliance? | 01/01/70 00:00 | |
| Theory vs. practice | 01/01/70 00:00 | |
| Jan is right: 7 | 01/01/70 00:00 | |
| I did not say 7! | 01/01/70 00:00 | |
| Interesting | 01/01/70 00:00 | |
| POP SP? :-) | 01/01/70 00:00 | |
| POP SP | 01/01/70 00:00 | |
| MOV SP,#SP | 01/01/70 00:00 | |
| exceptions and rules | 01/01/70 00:00 | |
| MOV A,ACC | 01/01/70 00:00 | |
| xxx a,acc | 01/01/70 00:00 | |
| if the "Bible says"... | 01/01/70 00:00 | |
| more interesting | 01/01/70 00:00 | |
| Hmmm.... interesting indeed! | 01/01/70 00:00 | |
| native doing | 01/01/70 00:00 | |
| Makes sense to me | 01/01/70 00:00 | |
| POP SP | 01/01/70 00:00 | |
| Output of SP | 01/01/70 00:00 | |
| Simulators | 01/01/70 00:00 | |
| simulators give me 7 7 | 01/01/70 00:00 | |
| 7 7 | 01/01/70 00:00 | |
| spent for which purpose | 01/01/70 00:00 | |
| Fun... | 01/01/70 00:00 | |
| Atmel and Philips | 01/01/70 00:00 | |
SiLabs F120 | 01/01/70 00:00 |