Renesas RL78/G1P Hardware User Manual page 517

RL78/G1P
12.5.13 Wakeup function
2
The I C bus slave function is a function that generates an interrupt request signal (INTIICAn) when a local address and
extension code have been received.
This function makes processing more efficient by preventing unnecessary INTIICAn signal from occurring when
addresses do not match.
When a start condition is detected, wakeup standby mode is set. This wakeup standby mode is in effect while
addresses are transmitted due to the possibility that an arbitration loss may change the master device (which has
generated a start condition) to a slave device.
To use the wakeup function in the STOP mode, set the WUPn bit to 1. Addresses can be received regardless of the
operation clock. An interrupt request signal (INTIICAn) is also generated when a local address and extension code have
been received. Operation returns to normal operation by using an instruction to clear (0) the WUPn bit after this interrupt
has been generated.
Figure 12-22 shows the flow for setting WUPn = 1 and Figure 12-23 shows the flow for setting WUPn = 0 upon an
address match.
Remark n = 0, 1
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
Figure 12-22. Flow When Setting WUPn = 1
START
MSTSn = STDn = EXCn = COIn =0?
Yes
WUPn = 1
Wait
STOP instruction execution
CHAPTER 12 SERIAL INTERFACE IICA
No
Waits for 3 clocks.
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