Renesas M16C FAMILY Hardware Manual page 167

Under development
Preliminary specification
Specifications in this manual are tentative and subject to change.
R8C/11 Group
Transfer a ring oscillator mode (main clock stop)
program to any area other the flash memory
Jump to the ring oscillator mode (main clock stop)
program which has been transferred to any area
other the flash memory.
(The subsequent processing is executed by a
program in any area other than the flash memory.)
Notes:
1. Set the FMR01 bit to "1" (CPU rewrite mode) before setting the FMSTP bit to "1" .
2. Before the clock source for CPU clock can be changed, the clock to which to be changed must be stable.
3. Insert a 10 µs wait time in a program. Avoid accessing to the flash memory during this wait time.
Figure 17.6 Processing Before and After Ring Oscillator Mode (Main Clock Stop)
Rev.0.91 2003 Sep 08 page 157 of 184
Ring oscillator mode (
main clock stop) program
Set the FMR01 bit by writing "0" and then "1"
(CPU rewrite mode enabled)
Set FMSTP bit to "1"
(flash memory stopped. Low power state)
Switch the clock source for CPU clock.
Turn X off
IN
Process of ring oscillator mode (main
clock stop)
wait until oscillation stabilizes
Turn main clock on
switch the clock source for CPU clock
Set the FMSTP bit to "0" (flash memory operation)
Write "0" to the FMR01 bit
(CPU rewrite mode disabled)
Wait until the flash memory circuit stabilizes
(10 µs)
3
Jump to a specified address in the flash memory
17.4 CPU Rewrite Mode
1
2