| ??? 06/09/11 15:58 Read: times |
#182557 - Not sufficient! Responding to: ???'s previous message |
Michael Brown said:
* S52 loads bootloader from internal ROM, which loads code into external RAM using MOVX Remember that MOVX writes to XDATA space - there is no way to write to CODE space! Therefore you also need some way to switch the RAM between XDATA space (for writing) and CODE space (for executing)... |
| 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 |