Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Wait Mode
Wait Mode
When a WAIT instruction is executed, BCLK stops and the microcomputer enters the wait mode. In this
mode, oscillation continues but 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 1.12.3 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 1.12.3. Port status during wait mode
Pin
Memory expansion mode
Microprocessor mode
Single-chip mode
_______
_______
Address bus, data bus, CS0 to CS3
_____ ______ ________ ________ _________
RD, WR, BHE, WRL, WRH
__________
Retains status before wait mode
“H”
HLDA,BCLK
“H”
ALE
Port
“H”
Retains status before wait mode
Retains status before wait mode
CLKOUT
When fC selected
Valid only in single-chip mode Does not stop
When f8, f32 selected Valid only in single-chip mode 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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MITSUBISHI [ Mitsubishi Group ]
