M16623FC datasheet(32/242 Pages) RENESAS

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Mitsubishi microcomputers

M16C / 62A Group (80-pin)

SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Wait Mode

Table 1.9.3. Port status during wait mode

Single-chip mode

Port

Retains status before wait mode

CLKOUT

When fC selected

Does not stop

When f8, f32 selected Does not stop when the WAIT peripheral function clock stop bit

is “0”.

When the WAIT peripheral function clock stop bit is “1”, the sta-

tus immediately prior to entering wait mode is retained.

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. However, peripheral function clock fC32

does not stop so that the peripherals using fC32 do not contribute to the power saving. When the MCU

running in low-speed or low power dissipation mode, do not enter WAIT mode with this bit set to “1”. Table

1.9.3 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, that

interrupt must first have been enabled, and the priority level of the interrupt which is not used to cancel must

have been changed to 0. If returning by an interrupt, the clock in which the WAIT instruction executed is set

to BCLK by the microcomputer, and the action is resumed from the interrupt routine. If only a hardware

_______

reset or an NMI interrupt is used to cancel wait mode, change the priority level of all interrupt to 0,then shift

to wait mode.

M16623FC Datasheet(PDF) 32 Page - Renesas Technology Corp