seemanta
Member level 4
power down mode 8051
Hi,
I have an RTC chip (DS12887) that periodically asserts the IRQ line which is connected to the INT0 line of my AT89S52.
I have seen that if my micro is in idle mode, the ISR for INT0 gets called periodically, without any intervention.
However, if my micro is in power down mode, the ISR does not get called. In power down mode the only way to invoke the ISR is to short the INT0 pin to the ground momentarily.
I am not able to understand why manually shorting to ground works in PD mode but asserting the IRQ line from the RTC does not work. :-(
Any help/pointers? Because of this, I am not able to implement power down mode in my digital clock :-(
Idle mode seems to work but it is power down mode in which I am more interested.
Any help would be greatly appreciated!
P.S. As per the data sheet, AT89S52 does seem to wakeup from power down mode by external interrupt. I am therefore clueless why this is not working !! :-(
Hi,
I have an RTC chip (DS12887) that periodically asserts the IRQ line which is connected to the INT0 line of my AT89S52.
I have seen that if my micro is in idle mode, the ISR for INT0 gets called periodically, without any intervention.
However, if my micro is in power down mode, the ISR does not get called. In power down mode the only way to invoke the ISR is to short the INT0 pin to the ground momentarily.
I am not able to understand why manually shorting to ground works in PD mode but asserting the IRQ line from the RTC does not work. :-(
Any help/pointers? Because of this, I am not able to implement power down mode in my digital clock :-(
Idle mode seems to work but it is power down mode in which I am more interested.
Any help would be greatly appreciated!
P.S. As per the data sheet, AT89S52 does seem to wakeup from power down mode by external interrupt. I am therefore clueless why this is not working !! :-(