4500/720 Series 720 Family Models 4513, 4514 Group User's Manual

4513/4514 Group User’s Manual

HARDWARE

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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.

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

s) is

passed from the voltage comparator function become valid.

LIST OF PRECAUTIONS