RTC - 72421 / 72423

„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

Check the status of the BUSY bit

STOP and RESET the counter

Set the current time in the registers

(initialize the S1 to W registers)

(A)At ths point, there is no need to check the BUSY bit.

(B)

(C)

 

 

 

Start the counter and release

(A)

the HOLD status

 

 

 

 

 

 

 

To next process

From here on, check the status of the BUSY bit before accessing any of the registers, except for the CD, CE and CF control register.

For details of processes (A) to (C), see next page.

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