| ??? 06/09/11 18:56 Read: times |
#182562 - do You need EA controlled? Responding to: ???'s previous message |
i mean:
First 8kB of code can be allways active, bootloader has to be started allways on every reset. Bootloader examines some condition - port/pin state, serial comm timeout or something other. If condition is true - bootloader stays in reprogramming mode, if its false - check application CRC and if ok - jump to application entry point. Reprogramming can be done in SRAM or in serial EPROM. Off cource this can be done in modern 64kB flash chips without using Code SRAM. SRAM/EEPROM method can be used for code>64k on limited to 64k device. regard |
| Topic | Author | Date |
| Bootloading using external RAM and EA switching? | 01/01/70 00:00 | |
| Not sufficient! | 01/01/70 00:00 | |
| Use single SRAM chip by tying PSEN to RD? | 01/01/70 00:00 | |
| That qualifies as... | 01/01/70 00:00 | |
| Experimentation ;) | 01/01/70 00:00 | |
| No need for experimentation | 01/01/70 00:00 | |
| Fast-forward to 2010 or thereabouts | 01/01/70 00:00 | |
| It would be a pretty narrow window, but ... | 01/01/70 00:00 | |
| methinks the real reason | 01/01/70 00:00 | |
| That's true for program updates, but ... | 01/01/70 00:00 | |
| visualizing any case where the regular ISP/IAP is too slow | 01/01/70 00:00 | |
| ... and FRAM's pretty fast, too ... | 01/01/70 00:00 | |
Would have liked to have used FRAM... | 01/01/70 00:00 | |
| As long as intervening RESET | 01/01/70 00:00 | |
| do You need EA controlled? | 01/01/70 00:00 | |
| hmm | 01/01/70 00:00 | |
| not surprised | 01/01/70 00:00 | |
| Decided not to use EA (rather, shouldn't) | 01/01/70 00:00 | |
| i'm confused by AT89S52 | 01/01/70 00:00 | |
| This is the page I found | 01/01/70 00:00 | |
| great | 01/01/70 00:00 |