| ??? 10/05/09 14:41 Read: times |
#169437 - Good checksumming Responding to: ???'s previous message |
Most microcontrollers draws too much for use with battery-backed RAM since the power will also drive the processor core, I/O pins, ... Because of this, some (haven't seen any 8051-compatible) microcontrollers have a separate supply pin for driving an RTC and battery-backed RAM. If the processor doesn't have a separate Vbatt input, then you will have to do your best to stop everything you can in the processor to reduce the power consumption from the battery.
Depending on memory technology, the memory may have random contents on initial power-up. Because of this, you will need a strong checksum to figure out if your configuration is random garbage, or good values kept since previous run. You will have to adapt the strength of the checksum to the cost/danger of incorrectly accepting random data as a valid configuration. |
| Topic | Author | Date |
| A few questions about internal RAM | 01/01/70 00:00 | |
| questions | 01/01/70 00:00 | |
| through everything | 01/01/70 00:00 | |
| oops | 01/01/70 00:00 | |
| maybe | 01/01/70 00:00 | |
| I'm writing in asm | 01/01/70 00:00 | |
| EEPROM | 01/01/70 00:00 | |
| then RAM is NOT cleared on reset | 01/01/70 00:00 | |
| RE: RAM is NOT cleared on reset. | 01/01/70 00:00 | |
| nothing in the code | 01/01/70 00:00 | |
| RAM indeterminate after a hardware reset | 01/01/70 00:00 | |
| Great | 01/01/70 00:00 | |
| Good checksumming | 01/01/70 00:00 | |
| Please pardon my ignorance | 01/01/70 00:00 | |
| Knowing if initial contents is initialized or not. | 01/01/70 00:00 | |
| Battery-backed microcontroller | 01/01/70 00:00 | |
| Just use an 8051 with eeprom | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| alternatives | 01/01/70 00:00 | |
| Not just "alternative" - but "superior"! | 01/01/70 00:00 | |
| Great suggestions | 01/01/70 00:00 | |
that depends | 01/01/70 00:00 |