| ??? 09/24/12 04:57 Read: times |
#188429 - Brain Fade ? Responding to: ???'s previous message |
Rick Gebhardt said:
.org H'20 .db 1,2,3,4,5,6,7,8, 1,2,3,4,5,6,7,8 (16 bytes) start: mov dptr,#H'20 (89C51's internal ram 0..FF) mov R7,#H'10 (A51 compiler uses H'10) loop: movx A,@dptr mov P1,A (with leds on P1 and a delay, I could see the bytes) inc dptr djnz R7,loop done: sjmp * .db is going to place bytes in CODE/ROM, whilst MOVX reads from XDATA. mov dptr,#H'20, then movx A,@dptr, is not going to read CODE. XDATA also needs to be enabled - so usually you would * enable XDATA * use MOVC to read Code/Flash * use MOVX to write to XDATA then * Use MOVX to read XDATA. Note you can set the 6440 to AutoINC the DPTR on most opcodes, and also use ALT DPTR opcodes to speed up transfers. |
| Topic | Author | Date |
| .db instr does not work like before with movx A,@dptr | 01/01/70 00:00 | |
| Brain Fade ? | 01/01/70 00:00 | |
| memory access | 01/01/70 00:00 | |
| Did you ever try the Maxim/Dallas DS89C4x0? | 01/01/70 00:00 | |
| Handle the dptr with care... | 01/01/70 00:00 | |
| Dallas, Dptr, and DB | 01/01/70 00:00 | |
| not really | 01/01/70 00:00 | |
| Perhaps what he means is ... | 01/01/70 00:00 | |
| Make no mistake... | 01/01/70 00:00 | |
| and also the XMEGA | 01/01/70 00:00 | |
| XMEGA ADC | 01/01/70 00:00 | |
I agree... | 01/01/70 00:00 | |
| those samples that Andy and others were expecting | 01/01/70 00:00 | |
| Is it 2007 already?? | 01/01/70 00:00 | |
| That's why I refer to them as MAXIM/DALLAS | 01/01/70 00:00 | |
| Part Numbers ? | 01/01/70 00:00 | |
| None in particular ... | 01/01/70 00:00 |