| ??? 08/18/05 05:54 Read: times |
#99616 - Answer for puzzle Responding to: ???'s previous message |
1. Since running from flah /EA is not pulled low.So PSEN won't go low.
2. When code is fetched from 8000h it should read contents of P0 so bytes read would be 0x0,0x1,0x2 as no memory is putting data on bus. 3. First is nop. 4. 0102 is ajmp 0x2. So code jumps to 0x2. That is nop again at 0x2. 5. Then code uses r2,r3 to back up dptr. DPTR now cotains value 0x0034. 5.Thus next read write tests take place at nonexitant RAM location and so fail. code jumps to ERROR and you get the error LED on as well. |
| Topic | Author | Date |
| week puzzle III | 01/01/70 00:00 | |
| Not getting into details... | 01/01/70 00:00 | |
| you do | 01/01/70 00:00 | |
| see this | 01/01/70 00:00 | |
| Well. . . | 01/01/70 00:00 | |
| let me try | 01/01/70 00:00 | |
| eh? | 01/01/70 00:00 | |
| I`m confused with A15 | 01/01/70 00:00 | |
| Whooops | 01/01/70 00:00 | |
| and I thought that was "the puzzle" | 01/01/70 00:00 | |
| sorry | 01/01/70 00:00 | |
| and I thought that was "the puzzle" | 01/01/70 00:00 | |
| another trouble | 01/01/70 00:00 | |
| And what's wrong with /CS? | 01/01/70 00:00 | |
| sorry, my mistake | 01/01/70 00:00 | |
| what does not happend? | 01/01/70 00:00 | |
| And...? | 01/01/70 00:00 | |
| explain | 01/01/70 00:00 | |
| And...? | 01/01/70 00:00 | |
| Answer for puzzle | 01/01/70 00:00 | |
| I doubt? | 01/01/70 00:00 | |
| I doubt | 01/01/70 00:00 | |
| I agree here | 01/01/70 00:00 | |
| I wonder | 01/01/70 00:00 | |
| autodetect | 01/01/70 00:00 | |
| /PSEN | 01/01/70 00:00 | |
| there is also flaw in the reasoning | 01/01/70 00:00 | |
| Lost inverter | 01/01/70 00:00 | |
| errta | 01/01/70 00:00 | |
| Questions | 01/01/70 00:00 | |
| answers to questions | 01/01/70 00:00 | |
| Timings | 01/01/70 00:00 | |
| Ex[plain A bit more please | 01/01/70 00:00 | |
| intel app note says | 01/01/70 00:00 | |
| I do | 01/01/70 00:00 | |
| re:EA | 01/01/70 00:00 | |
| yes no doubt about it | 01/01/70 00:00 | |
| reset device | 01/01/70 00:00 | |
| three legged | 01/01/70 00:00 | |
The solution | 01/01/70 00:00 |