Epson S1C63000 - Manual (Page 38)

32 EPSON S1C63000 CORE CPU MANUAL
CHAPTER 3: CPU OPERATION
During SLEEP status, as in the HALT status, the contents of the registers in the CPU that have been set
before shifting are maintained if rated voltage is supplied.
Figure 3.6.2.1 shows the sequence of shifting to the SLEEP status and restarting.
When an interrupt that releases the SLEEP status is generated, the oscillation circuit begins to oscillate.
When the oscillation starts, the CLK input to the CPU is masked by the peripheral circuit and the input to
the CPU begins after stabilization waiting time (several 10 msec–several msec) has elapsed. The CPU
samples the interrupt at the falling edge of the initially input CLK and starts the interrupt processing.
OSC
CLK
PK
PL
PC
FETCH
DBS1/0
STOP
IRQ
T1
SLP
pc
0 2
pc+1
Interrupt processing
T2 T3 T4
DUMMY
ANY
T1T2 T3 T4
SLEEP status
Oscillation stable
waiting time
Fig. 3.6.2.1 Sequence of the shift to SLEEP status and restarting