| ??? 02/08/05 17:18 Read: times |
#86943 - ch3 pg 6 Responding to: ???'s previous message |
Whenever a 16-bit address is used, the high byte of the address
comes out on Port 2, where it is held for the duration of the read or write cycle. Note that the Port 2 drivers use the strong pullups during the entire time that they are emitting address bits that are 1s. This is during the execution of a MOVX @DPTR instruction. During this time the Port 2 latch (the Special Function Register) does not have to contain 1s, and the contents of the Port 2 SFR are not modified. If the external memory cycle is not immediately followed by another external memory cycle, the undisturbed contents of the Port 2 SFR will reappear in the next cycle. |
| Topic | Author | Date |
| P2:R0 as memory pointer | 01/01/70 00:00 | |
| Read the cpu data! | 01/01/70 00:00 | |
| P2 readback | 01/01/70 00:00 | |
| Re | 01/01/70 00:00 | |
| Thank you all | 01/01/70 00:00 | |
| Interesting | 01/01/70 00:00 | |
| very well described | 01/01/70 00:00 | |
| This is NOT in the | 01/01/70 00:00 | |
| ch3 pg 6 | 01/01/70 00:00 | |
| none of them | 01/01/70 00:00 | |
| more | 01/01/70 00:00 | |
| An experiment - AT89C8252 | 01/01/70 00:00 | |
| not necessarily | 01/01/70 00:00 | |
| sure not necessarily | 01/01/70 00:00 | |
| talking about memory | 01/01/70 00:00 | |
| MOVX multiplexed with P2 SFR data | 01/01/70 00:00 | |
| Now I say: HUH | 01/01/70 00:00 | |
| huh | 01/01/70 00:00 | |
| Thank you | 01/01/70 00:00 | |
| what datasheet says | 01/01/70 00:00 | |
| I should've RTFM... :-) | 01/01/70 00:00 | |
| not too much logic | 01/01/70 00:00 | |
| sure | 01/01/70 00:00 | |
| The horses mouth | 01/01/70 00:00 | |
| horse is plural | 01/01/70 00:00 | |
| I'd be happy to ... | 01/01/70 00:00 | |
| can't find them | 01/01/70 00:00 | |
As you use to say :) | 01/01/70 00:00 | |
| another note | 01/01/70 00:00 |