M16C6K9 Datasheet, PDF (35/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
Wait Mode
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 func-
tion 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, because the peripheral function clock (fc32)
that is generated by sub clock does not stop, there is no reducing of power dissipation. Do not set the bit to
"1" then enter wait mode in low speed mode and low power dissipation mode.Table.WA-3 shows the status
of the ports in wait mode.
Wait mode is cancelled by a hardware reset or interrupt. If an interrupt is used to cancel wait mode, the
microcomputer restarts from interrupt routine using as BCLK, the clock that had been selected when the
WAIT instruction was executed.
Table.WA-3 Port status during wait mode
Pin
Single-chip 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
status immediately prior to entering wait mode is maintained.
Port
maintained the status immediately prior to enterig wait mode
Rev.1.00 Jun 06, 2003 page 35 of 290