Datasheet

RL78/L12 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0330EJ0200 Rev.2.00 467
Dec 13, 2013
12.5.7 SNOOZE mode function
SNOOZE mode makes CSI operate reception by SCKp pin input detection while the STOP mode. Normally CSI stops
communication in the STOP mode. But, using the SNOOZE mode makes reception CSI operate unless the CPU operation
by detecting SCKp pin input.
Only the following channel can be set to the SNOOZE mode.
CSI00
When using the CSI in SNOOZE mode, make the following setting before switching to the STOP mode (see Figure 12-
70 Flowchart of SNOOZE Mode Operation (once startup) and Figure 12-72 Flowchart of SNOOZE Mode Operation
(continuous startup)).
• When using the SNOOZE mode function, set the SWCm bit of serial standby control register m (SSCm) to 1 just
before switching to the STOP mode. After the initial setting has been completed, set the SSm1 bit of serial channel
start register m (SSm) to 1.
After a transition to the STOP mode, the CSI starts reception operations upon detection of an edge of the SCKp pin.
Cautions 1. The SNOOZE mode can only be specified when the high-speed on-chip oscillator clock is selected
for f
CLK.
2. The maximum transfer rate when using CSIp in the SNOOZE mode is 1 Mbps.
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