| ??? 09/26/07 13:00 Read: times |
#145006 - no Responding to: ???'s previous message |
Erik Malund said:
what you say has NOTHING to do with RAM after reset it is about RAM after programming
I do appreciate that you bring up the iossue since many have been fooled by it, bot this is not after reset. "the bible" still holds. Erik No, in the case of P89V51RD2, the sheer fact that the bootloader runs before the user application, corrupts a couple of bytes in the RAM, even if the autobauding (and subsequent operations including programming) does NOT happen! So, in other words, the "bible" holds for the 'V51RD2 as a whole, i.e. after warm reset the RAM still contains what it contained before reset, it's just that the bootloader is executed BEFORE the application - and that the default bootloader is flawed in this particular way. But, from the application point of view, the bootloader "wait for autobauding" is invisible and seen as part of a reset "process", so, from the application point if view, the "biblical" behaviour is violated. JW |
| Topic | Author | Date |
| Memory of AT89C2051 after reset | 01/01/70 00:00 | |
| this is relatively complicated... | 01/01/70 00:00 | |
| Why no reset during low power? | 01/01/70 00:00 | |
| during active reset the oscillator is running... | 01/01/70 00:00 | |
| power back up? | 01/01/70 00:00 | |
| Oh, certainly... | 01/01/70 00:00 | |
| thanks | 01/01/70 00:00 | |
| alternatives | 01/01/70 00:00 | |
| options? | 01/01/70 00:00 | |
| my way of doing this... | 01/01/70 00:00 | |
| Then jus a RAM chip would work | 01/01/70 00:00 | |
| wouldn't it be easier and safer with serial EEPROM | 01/01/70 00:00 | |
| Maybe | 01/01/70 00:00 | |
| why not FRAM | 01/01/70 00:00 | |
| Combination of Technologies.... | 01/01/70 00:00 | |
| SRAM | 01/01/70 00:00 | |
| I don't think so | 01/01/70 00:00 | |
| this is not matter of "thinking"! | 01/01/70 00:00 | |
| OK, an another gotcha | 01/01/70 00:00 | |
| to Jan | 01/01/70 00:00 | |
| no | 01/01/70 00:00 | |
here is the best chip for u! | 01/01/70 00:00 |