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CHAPTER 9 8-BIT TIMER/EVENT COUNTER
(1) 8-bit compare registers (CR10 and CR20)
These 8-bit registers always compare their set values with the count values of the 8-bit timer registers 1 and
2 (TM1 and TM2). CR10 compares its set value with TM1, while CR20 compares its set value with TM2. When
the value of a compare register coincides with the count value of the corresponding timer register, the compare
register generates an interrupt request (INTTM1 or INTTM2).
When TM1 or TM2 is used as an interval timer, the corresponding compare register can also be used to hold
interval time.
CR10 and CR20 are set by an 8-bit memory manipulation instruction, and cannot be set by a 16-bit memory
manipulation instruction. When TM1 and TM2 are used as 8-bit timer/event counters, a value in a range of
00H-FFH can be set to the corresponding compare registers. When the two 8-bit timer/event counters are
used in combination as a 16-bit timer/event counter, a value in a range of 0000H-FFFFH can be set to the
two compare registers.
The contents of these registers become undefined when the RESET signal is input.
Caution Set data to these registers when the two 8-bit timer/event counters are used as a 16-bit timer/
event counter after stopping the operation of the timer.
(2) 8-bit timer registers 1 and 2 (TM1 and TM2)
These 8-bit registers count the number of count pulses.
When TM1 and TM2 are used individually, the value of each timer register can be read by an 8-bit memory
manipulation instruction. When the two timer registers are used in combination as a 16-bit timer, the value
of the 16-bit timer register (TMS) can be read by a 16-bit memory manipulation instruction.
These registers are initialized to 00H when the RESET signal is input.