Thanks every one for your inputs.

I will clarify (???) further :

1) It is not my intention to use the DS1232 as a watchdog IC as the same can be done internally in the 89C51RD2BN( built in ). The idea is only to use the IC for power supervision and push button reset instead of an RC network.The behaviour I had noticed was that when the ALE pin is connected the chip behaves perfectly i.e. the RST is kept solid low. However when the ALE is disconnected and the RST is also disconnec ted from the micro , the RST pin on the DS1232 does not maintain a constant high , it varies from 4.9 V to 2.3 V in a cyclic manner ( oscillation ;-) ). I think that it should maintain 4.9 V constant. Maybe a problem with the particular chip ??

2) The reason I am using 9V battery is to keep the size compact instead of 4 x 1.5 V. Anyway I am working on keeping the LCD on only when the user pushes a button by using one of the spare port pins and then timing it off. Anyother other suggestions to work on power reduction ??


Thomas