Renesas 4514 - Manual (Page 190)

4513/4514 Group User’s Manual
APPENDIX
3-23
3.3 List of precautions
16 Voltage comparator function
When the voltage comparator function is valid with the voltage
comparator control register Q3, it is operating even in the RAM
back-up mode. Accordingly, be careful about such state because
it causes the increase of the operation current in the RAM back-
up mode.
In order to reduce the operation current in the RAM back-up
mode, invalidate (bits 2 and 3 of register Q3 = “0”) the voltage
comparator function by software before the POF instruction is ex-
ecuted.
Also, while the voltage comparator function is valid, current is al-
ways consumed by voltage comparator. On the system required
for the low-power dissipation, invalidate the voltage comparator
when it is unused by software.
Register Q3
Bits 0 and 1 of register Q3 can be only read. Note that they can-
not be written.
Reading the comparison result of voltage comparator
Read the voltage comparator comparison result from register Q3
after the voltage comparator response time (max. 20
µ
s) is
passed from the voltage comparator function become valid.
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