M16C62_N Datasheet, PDF (61/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

Wait Mode
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Wait Mode
When a WAIT instruction is executed, the BCLK stops and the microcomputer enters the wait mode. In this
mode, oscillation continues but the BCLK and watchdog timer stop. Writing “1” to the WAIT peripheral
function clock stop bit and executing a WAIT instruction stops the clock being supplied to the internal
peripheral functions, allowing power dissipation to be reduced. Table 1.13.3 shows the status of the ports in
wait mode.
Wait mode is cancelled by a hardware reset or an interrupt. If an interrupt is used to cancel wait mode, the
microcomputer restarts from the interrupt routine using as BCLK, the clock that had been selected when the
WAIT instruction was executed.
Table 1.13.3. Port status during wait mode
Pin
Memory expansion mode
_______
_______
Address bus, data bus, CS0 to CS3,
________
BHE
_____ ______ ________ _________
RD, WR, WRL, WRH
__________
HLDA,BCLK
Microprocessor mode
Retains status before wait mode
“H”
“H”
ALE
“H”
Port
Retains status before wait mode
CLKOUT
When fC selected Valid only in single-chip mode
When f8, f32 selected Valid only in single-chip mode
Single-chip mode
Retains status before wait mode
Does not stop
Does not stop when the WAIT
peripheral function clock stop
bit is “0”.
When the WAIT peripheral
function clock stop bit is “1”,
the status immediately prior
to entering wait mode is main-
tained.
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