RL78/G13 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0146EJ0100 Rev.1.00 661
Sep 22, 2011
(3) SNOOZE mode operation (Abnormal Operation <2>)
Abnormal operation <2> is the operation performed when a communication error occurs while SSECm = 1.
Because SSECm = 1, an error interrupt (INTSREq) is not generated when a communication error occurs.
Figure 12-94. Timing Chart of SNOOZE Mode Operation (Abnormal Operation <2>)
SSm1
SEm1
SWCm
SSECm
SDRm1
INTSRq
INTSREq
L
TSFm1
STm1
Note 2
P
ST
P
SP SP
ST
<5><6><7>
RxDq pin
CPU operation status
Normal operation
Normal
operation
STOP mode
Clock request signal
(internal signal)
SNOOZE mode
<1> <2> <3> <5>
<6>
<4>
Shift
register m1
Data reception (7-bit length)Data reception (7-bit length)
Receive data 2
Receive data 2
Receive data 1
Receive data 1
<9>
Read
Note1
Shift operationShift operation
STOP mode SNOOZE mode
<7>,
<8>
Notes 1. Only read received data while SWCm = 1 and before the next edge of the RxDq pin input is detected.
2. After UARTq successfully finishes reception in the SNOOZE mode, it is possible to continue to perform
normal reception operations without changing the settings, but, because SSECm = 1, the PEFm1 and
FEFm1 bits are not set even if a framing error or parity error occurs. In addition, no error interrupt
(INTSREq) is generated.
Cautions 1. Before switching to the SNOOZE mode or after reception operation in the SNOOZE mode
finishes, be sure to set the STm1 bit to 1 and clear the SEm1 bit (to stop the operation).
2. When using the SNOOZE mode while SSECm is set to 1, no overrun errors occur. Therefore,
when using the SNOOZE mode, read bits 7 to 0 (RxDq) of the SDRm1 register before switching
to the STOP mode.
Remarks 1. <1> to <9> in the figure correspond to <1> to <9> in Figure 12-95. Flowchart of SNOOZE Mode
Operation (Abnormal Operation <2>).
2. 24 to 64-pin products: m = 0; q = 0
80, 100, 128-pin products: m = 0, 1; q = 0, 2
<R>
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