M16CSLASH29 datasheet(447/499 Pages) RENESAS

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22. Usage Notes

page 423

22.2.2 Power Control

1. When exiting stop mode by hardware reset, the device will startup using the on-chip oscillator.

2. Set the MR0 bit in the TAiMR register(i=0 to 4) to 0 (pulse is not output) to use the timer A to exit stop

mode.

3. When entering wait mode, insert a JMP.B instruction before a WAIT instruction. Do not excute any

instructions which can generate a write to RAM between the JMP.B and WAIT instructions. Disable the

DMA transfers, if a DMA transfer may occur between the JMP.B and WAIT instructions. After the WAIT

instruction, insert at least 4 NOP instructions. When entering wait mode, the instruction queue reads

ahead the instructions following WAIT, and depending on timing, some of these may execute before the

MCU enters wait mode.

Program example when entering wait mode

Program Example:

JMP.B

; Insert JMP.B instruction before WAIT instruction

L1:

FSET

;

WAIT

; Enter wait mode

NOP

; More than 4 NOP instructions

NOP

4. When entering stop mode, insert a JMP.B instruction immediately after executing an instruction which

sets the CM10 bit in the CM1 register to 1, and then insert at least 4 NOP instructions. When entering

stop mode, the instruction queue reads ahead the instructions following the instruction which sets the

CM10 bit to 1 (all clock stops), and, some of these may execute before the MCU enters stop mode or

before the interrupt routine for returning from stop mode.

Program example when entering stop mode

Program Example:

FSET

BSET

CM10

; Enter stop mode

JMP.B

; Insert JMP.B instruction

L1:

NOP

; More than 4 NOP instructions

NOP

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