RX − 8564 LC

3) Example of processing to recover from backup mode

Backup recovery

processing

 

∗ 1

No ( VL = " 1 " )

∗ 2

 

 

∗ 1) Check the VL bit (Voltage Low Flag).

VL = " 0 " ?

 

 

 

 

 

 

 

∗ 3

∗ 2) When the VL bit = "1", it may be due to

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

an error during backup (clock data or

 

 

 

 

 

 

 

( VL = " 0 " )

 

 

Initialization

 

 

register settings may have been lost,

 

 

 

 

due to a voltage drop, etc.), so be sure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

to initialize.

 

 

 

 

 

 

 

 

 

∗ 3) Be sure to initialize all registers. (For

 

 

 

 

 

 

 

 

 

further description of initialization, see

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

"Initialization" below.)

To next process

 

 

 

 

 

 

 

 

4) Example of clock and calendar write processing

Set current time

STOP ← " 1 "

Write current time

STOP ← " 0 "

•Write "1" to the STOP bit to prevent clock updates while setting the current time.

•Write the data (among the [Year/Month/Day [day of week]:hour:minute:second] data) that needs to be set (or reset).

∗When initializing be sure to initialize all of the data.

•Zero-clear the STOP bit to start (restart) the clock's operation.

∗The clock starts from the set [second] + 500 ms (500 ms after the set second). (The first [second] update occurs 500 ms later.)

To next process

5)Example of clock and calendar read processing

Read current time

Read current time

• The required information (among the [Year/Month/Day [day of

week]:hour:minute:second] data) is read within one second.

 

 

∗ There is no need to manipulate the STOP bit.

 

 

 

 

 

To next process

 

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ETM12E-01