Epson RTC-72421 A - Manual (Page 17)

RTC - 72421 / 72423
Page - 14 MQ - 162 - 03
„ Using the RTC-72421/RTC-72423
1. Power-on procedure (initialization)
When power is turned on, the contents of all registers and the output from the STD.P pin are undefined. Therefore, all the registers
must be initialized after power on. Follow the procedure given below for initialization.
Power On
Start the counter
Initialize the control registers
To next process
Check the status of the BUSY bit
STOP and RESET the counter
Set the current time in the registers
(initialize the S 1 to W registers)
Start the counter and release
the HOLD status
(A)
(B)
(C)
(A)
At ths point, there is no need to
check the BUSY bit.
From here on, check the status of the
BUSY bit before accessing any of the
registers, except for the C
D , C E and C F
control register.
For details of processes (A) to (C), see next page.