| ??? 01/17/06 08:47 Modified: 01/17/06 08:49 Read: times Msg Score: +2 +2 Good Answer/Helpful |
#107567 - surprise Responding to: ???'s previous message |
I was halfway through writing something like "ALE cannot be disabled on standard '51 only on newer derivatives", but had a look into the datasheet and it says:
AT89C52 datasheet rev. 0313H-02/00 on page 4 said:
If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. Wow. To be more confused, there is no SFR at address 8Eh in the table on the very same page... (it is AUXREG in other derivatives). So, according to datasheet, orl 8Eh,#01h should disable the ALE under the conditions described above... Jan Waclawek |
| Topic | Author | Date |
| ALE disable | 01/01/70 00:00 | |
| surprise | 01/01/70 00:00 | |
Works like the AT89S52 | 01/01/70 00:00 |