Power Control
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
444
2.14.3 Wait Mode Set-Up
Figure 2.14.6. Example of wait mode set-up
Settings and operation for entering wait mode are described here.
(1) Enables the interrupt used for returning from wait mode.
(2) Sets the interrupt enable flag (I flag) to “1”.
(3) Clears the protection and changes the content of the system clock control register.
(4) Executes the WAIT instruction.
Operation
Wait mode
(3) Canceling protect
b7
b0
Protect register [Address 000A16]
PRCR
1
Enables writing to system clock control registers 0 and 1
(addresses 000616 and 000716)
1 : Write-enabled
(4) WAIT instruction
(3) Control of CPU clock
Note: When switching the system clock, it is necessary
to wait for the oscillation to stabilize.
b7
b0
WAIT peripheral function clock stop bit
0 : Do not stop f1, f8, f32 in wait mode
1 : Stop f1, f8, f32 in wait mode
Port XC select bit
0 : I/O port
1 : XCIN-XCOUT generation
Main clock (XIN-XOUT) stop bit
0 : On
1 : Off
Main clock division select bit 0
0 : CM16 and CM17 valid
1 : Division by 8 mode
System clock select bit (Note)
0 : XIN, XOUT
1 : XCIN, XCOUT
System clock control register 0
[Address 000616] CM0
b7
b0
System clock control register 1
[Address 000716] CM1
0000
Reserved bit
Must be set to “0”
Main clock division select bit
0 0 : No division mode
0 1 : Division by 2 mode
1 0 : Division by 4 mode
1 1 : Division by 16 mode
b7 b6
Interrupt control register
TBiIC(i=3 to 5)
[Address 004516 to 004716]
BCNIC
[Address 004A16]
KUPIC
[Address 004D16]
SiTIC(i=0 to 2)
[Address 005116, 005316, 004F16]
SiRIC(i=0 to 2)
[Address 005216, 005416, 005016]
TAiIC(i=0 to 4)
[Address 005516 to 005916]
TBiIC(i=0 to 2)
[Address 005A16 to 005C16]
(1) Setting interrupt to cancel wait mode
Make sure that the interrupt priority
level of the interrupt which is used
to cancel the wait mode is higher
than the processor interrupt priority
(IPL) of the routine where the
WAIT instruction is executed.
Interrupt priority level select bit
b7
b0
INTiIC(i=3)
[Address 004416]
SiIC/INTjIC (i=4, 3)
[Address 004816, 004916]
(j=3, 4)
[Address 004816, 004916]
INTiIC(i=0 to 2)
[Address 005D16 to 005F16]
Make sure that the interrupt priority level of the
interrupt which is used to cancel the wait mode is
higher than the processor interrupt priority (IPL) of
the routine where the WAIT instruction is executed.
Interrupt priority level select bit
b7
b0
0
Reserved bit
Must be set to “0”
(2) Interrupt enable flag (I flag)
“1”