| ??? 08/08/05 12:45 Read: times |
#98996 - my plans Responding to: ???'s previous message |
Dear Erik,
"AT89s52 DATASHEET" said:
If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With theb it 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." whenever i dont want to use data RAM i put it in low power mode by (!CS is connected to ALE) disabling the ALE. "AT89s52 DATASHEET" said:
Table 8. Status of External Pins During Idle and Power-down Modes Mode Program Memory ALE PSEN Idle Internal 1 1 Idle External 1 1 Power-down Internal 0 0 Power-down External 0 0 so when ever there is nothing to do i enter idle mode and RAM goes to LOW power mode. also ALE is connected to !CS during resets and brownouts RAM is disabled. Abhishek |
| Topic | Author | Date |
| Feeding the DS1232 Dog | 01/01/70 00:00 | |
| Why? | 01/01/70 00:00 | |
| Exixsting Board | 01/01/70 00:00 | |
| That makes mr REALLY curious, what reaso | 01/01/70 00:00 | |
| Exixsting Board | 01/01/70 00:00 | |
| no free ALE possible ! | 01/01/70 00:00 | |
| but it does not need to be if the purpos | 01/01/70 00:00 | |
| the reason what you dont beleave... | 01/01/70 00:00 | |
| but ALE is "just" ALE, not a GPIO, pleas | 01/01/70 00:00 | |
| my plans | 01/01/70 00:00 | |
| Use a buffer if using a XTAL | 01/01/70 00:00 | |
| wave forms | 01/01/70 00:00 | |
| Not trivial... | 01/01/70 00:00 | |
| Thanks Kai...... | 01/01/70 00:00 | |
| conclusion | 01/01/70 00:00 | |
| What exactly goes wrong? | 01/01/70 00:00 | |
| here is whats go wrong | 01/01/70 00:00 | |
| Ground bounce! | 01/01/70 00:00 | |
| Another board is only solution | 01/01/70 00:00 | |
| 3 or 4 Pin Supervisor is also a solution | 01/01/70 00:00 | |
| Pronouncing | 01/01/70 00:00 | |
| Prahlad and Kai | 01/01/70 00:00 | |
Communication Failure. | 01/01/70 00:00 |