Fujitsu FR60 Hardware Manual page 54

CHAPTER 2 HANDLING THE DEVICE
❍ Low-power consumption mode
(1) Be sure to use the following sequences after using the synchronous standby mode (TBCR:
Set by time base counter control register bit8 SYNCS bit) when putting in the standby mode.
/* Write to STCR */
ldi
ldi
stb
/* Write to CTBR */
ldi
ldi
stb
ldi
stb
/* Clear the time base counter at this point */
ldub
/* Start moving to synchronous standby mode */
ldub
nop
nop
nop
nop
nop
(2) Do not do the following when the monitor debugger is used.
- Set the break point to the above-mentioned instruction row.
- Execute the step for the above-mentioned instruction row.
❍ Prefetch
When allowing prefetch from an area that has been set as a little endian area, limit access to
the area to word access (i.e., access in units of 32 bits).
The area cannot be accessed correctly by byte or half-word accesses.
❍ I/O port access
Only byte accesses are allowed to I/O ports.
❍ Switching the function of a common port
Use the port function register (PFR) to switch the function of a pin which also serves as a port.
However, use an external bus setting to switch the function of a bus pin.
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#_STCR, r0 ; STCR register (481H)
#Val_of_Stby, rl ; "Val_of_Stby" is the data to be written to STCR.
rl, @r0 ; Write to STCR.
#_CTBR, r2 ; CTBR register (483H)
#0xA5, rl ; Clear command (1)
rl, @r2 ; Write A5 to CTBR.
#0x5A, rl ; Clear command (2)
rl, @r2 ; Write 5A to CTBR.
@r0, rl ; Read from STCR.
@r0, rl ; Dummy read from STCR.
; NOP for timing adjustment x 5