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CHAPTER 8 16-BIT TIMER/EVENT COUNTER
(1) Capture/compare register 00 (CR00)
CR00 is a 16-bit register which has the functions of both a capture register and a compare register. Whether
it is used as a capture register or as a compare register is set by bit 0 (CRC00) of capture/compare control
register 0.
When CR00 is used as a compare register, the value set in the CR00 is constantly compared with the 16-
bit timer register (TM0) count value, and an interrupt request (INTTM00) is generated if they match. It can
also be used as the register which holds the interval time when TM0 is set to interval timer operation, and
as the register which sets the pulse width in the PWM operating mode.
When CR00 is used as a capture register, it is possible to select the valid edge of the INTP0/TI00 pin or the
INTP1/TI01 pin as the capture trigger. Setting of the INTP0/TI00 or INTP1/TI01 valid edge is performed by
means of external interrupt mode register 0.
If CR00 is specified as a capture register and capture trigger is specified to be the valid edge of the INTP0/
TI00 pin, the situation is as shown in the following table.
Table 8-5. INTP0/TI00 Pin Valid Edge and CR00 Capture Trigger Valid Edge
ES11
ES10
INTP0/TI00 Pin Valid Edge
CR00 Capture Trigger Valid Edge
0
0
Falling edge
Rising edge
0
1
Rising edge
Falling edge
1
0
Setting prohibited
1
1
Both rising and falling edges
No capture operation
CR00 is set by a 16-bit memory manipulation instruction.
After RESET input, the value of CR00 is undefined.
(2) Capture/compare register 01 (CR01)
CR01 is a 16-bit register which has the functions of both a capture register and a compare register. Whether
it is used as a capture register or a compare register is set by bit 2 (CRC02) of capture/compare control register
0.
When CR01 is used as a compare register, the value set in the CR01 is constantly compared with the 16-
bit timer register (TM0) count value, and an interrupt request (INTTM01) is generated if they match.
When CR01 is used as a capture register, it is possible to select the valid edge of the INTP0/TI00 pin as the
capture trigger. Setting of the INTP0/TI00 valid edge is performed by means of external interrupt mode
register 0.
CR01 is set with a 16-bit memory manipulation instruction.
After RESET input, the value of CR01 is undefined.
(3) 16-bit timer register (TM0)
TM0 is a 16-bit register which counts the count pulses.
TM0 is read by a 16-bit memory manipulation instruction. When TM0 is read, capture/compare register (CR01)
should first be set as a capture register.
RESET input sets TM0 to 0000H.
Caution As reading of the value of TM0 is performed via CR01, the previously set value of CR01 is
lost.