M16C6KA_15 Datasheet, PDF (35/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Clock Generating Circuit
Clock Output
In single-chip mode, the clock output function select bits (bits 0 and 1 at address 000616) enable f8, f32 to be
output from the P57/CLKOUT pin. When the WAIT peripheral function clock stop bit (bit 2 at address 000616)
is set to “1”, the output of f8 and f32 stops when a WAIT instruction is executed.
By setting the f1 output function selection bits (bits 0 and 1 at address 02F116), the same frequency clock
with f(XIN) can be output from P110 and P111.
Stop Mode
Writing “1” to the all-clock stop control bit (bit 0 at address 000716) stops all oscillation and the microcom-
puter enters stop mode. In stop mode, the content of the internal RAM is retained provided that VCC remains
above 2V.
The oscillation , BCLK, f1 to f32, f1SIO2 to f32SIO2, and fAD stop in stop mode, peripheral functions such as the
A-D converter and watchdog timer do not function. However, timer A and timer B operate provided that the
event counter mode is set to an external pulse, and UART1, SIO3,4 functions provided an external clock is
selected. Table.WA-2 shows the status of the ports in stop mode.
Stop mode is cancelled by a hardware reset or interrupt. If an interrupt is to be used to cancel stop mode, that
interrupt must first have been enabled. After the restoration by interrupt, the corresponding interrupt routine
will be processed. When shifting from high speed mode or mid-speed mode to stop mode, the main clock
division select bit 0 (bit 6 at 000616) is set to “1”.
Table.WA-2 Port status during stop mode
Port
CLKOUT
Pin
When f8, f32 selected
Single-chip mode
Retains status before stop mode
Retains status before stop mode
Rev.1.00 Jul 16, 2004 page 33 of 266
REJ03B0100-0100Z