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M16C62_M Datasheet, PDF (494/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES | |||
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Power Control
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
System clock control register 0 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
CM0
Address
000616
When reset
4816
Bit symbol
CM00
CM01
CM02
CM03
Bit name
Clock output function
select bit
(Valid only in single-chip
mode)
WAIT peripheral function
clock stop bit
XCIN-XCOUT drive capacity
select bit (Note 2)
Function
RW
b1 b0
0 0 : I/O port P57
0 1 : fC output
1 0 : f8 output
1 1 : f32 output
0 : Do not stop peripheral function clock in wait mode
1 : Stop peripheral function clock in wait mode (Note 8)
0 : LOW
1 : HIGH
CM04
CM05
Port XC select bit
Main clock (XIN-XOUT)
stop bit (Note 3, 4, 5)
0 : I/O port
1 : XCIN-XCOUT generation (Note 9)
0 : On
1 : Off
CM06
Main clock division select 0 : CM16 and CM17 valid
bit 0 (Note 7)
1 : Division by 8 mode
CM07
System clock select bit
(Note 6)
0 : XIN, XOUT
1 : XCIN, XCOUT
Note 1: Set bit 0 of the protect register (address 000A16) to â1â before writing to this register.
Note 2: Changes to â1â when shiffing to stop mode and at a reset.
Note 3: When entering low power dissipation mode, main clock stops by using this bit. To stop the main clock, when the
sub clock oscillation is stable, set system clock select bit (CM07) to â1â before setting this bit to â1â.
Note 4: When inputting external clock, only clock oscillation buffer is stopped and clock input is acceptable.
Note 5: If this bit is set to â1â, XOUT turns âHâ. The built-in feedback resistor remains being connected, so XIN turns
pulled up to XOUT (âHâ) via the feedback resistor.
Note 6: Set port XC select bit (CM04) to â1â and stabilize the sub-clock oscillating before setting this bit from â0â to â1â.
Do not write to both bits at the same time. And also, set the main clock stop bit (CM05) to â0â and stabilize the
main clock oscillating before setting this bit from â1â to â0â.
Note 7: This bit changes to â1â when shifting from high-speed/medium-speed mode to stop mode and at a reset. When
shifting from low-speed/low power dissipation mode to stop mode, the value before stop mode is retained.
Note 8: fC32 is not included. Do not set to â1â when using low-speed or low power dissipation mode.
Note 9: When the XCIN/XCOUT is used, set ports P86 and P87 as the input ports without pull-up.
System clock control register 1 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
00 0 0
Symbol
CM1
Address
000716
When reset
2016
Bit symbol
Bit name
CM10
All clock stop control bit
(Note4)
Reserved bit
Function
0 : Clock on
1 : All clocks off (stop mode)
Must always be set to â0â
RW
Reserved bit
Must always be set to â0â
Reserved bit
Must always be set to â0â
Reserved bit
Must always be set to â0â
CM15
XIN-XOUT drive capacity
select bit (Note 2)
0 : LOW
1 : HIGH
CM16
CM17
Main clock division
select bit 1 (Note 3)
b7 b6
0 0 : No division mode
0 1 : Division by 2 mode
1 0 : Division by 4 mode
1 1 : Division by 16 mode
Note 1: Set bit 0 of the protect register (address 000A16) to â1â before writing to this register.
Note 2: This bit changes to â1â when shifting from high-speed/medium-speed mode to stop mode and at a reset. When
shifting from low-speed/low power dissipation mode to stop mode, the value before stop mode is retained.
Note 3: Can be selected when bit 6 of the system clock control register 0 (address 000616) is â0â. If â1â, division mode is
fixed at 8.
Note 4: If this bit is set to â1â, XOUT turns âHâ, and the built-in feedback resistor is cut off. XCIN and XCOUT turn high-
impedance state.
Figure 2.15.4. Power control-related registers
2-177
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