UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 277

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(1) Timer register 1 (TM1/TM1W)
(2) Compare register (CR10/CR10W)
(3) Capture/compare register (CR11/CR11W)
TM1//TM1W is a timer register that counts up using the count clock specified by the low-order 4 bits of prescaler mode
register 1 (PRM1).
The count operation can be specified to stop or enable, and an 8-bit operation mode (TM1)/16-bit operation mode (TM1W)
can be selected, by means of timer control register 1 (TMC1).
TM1/TM1W can be read only with an 8/16-bit manipulation instruction. When RESET is input, TM1/TM1W is cleared to 00H
and the count is stopped.
Caution Although the timer register can be read, if counting up the timer and reading the timer register conflict,
CR10/CR10W is an 8/16-bit register that holds the value that determines the interval timer operation cycle.
If the contents of the CR10/CR10W match the values of TM1/TM1W, an interrupt request (INTC10) is generated. This match
signal is also a real-time output port trigger signal. Also, the count value can be cleared by a match.
This compare register operates as CR10 in the 8-bit operating mode, and CR10W in the 16-bit operating mode.
CR10/CR10W can be read or written to with an 8/16-bit manipulation instruction. The contents of this register are undefined
after RESET input.
CR11/CR11W is an 8/16-bit register that can be specified as a compare register for detecting a match with the TM1/TM1W
count value or a capture register for capturing the TM1/TM1W count value according to the setting of capture/compare
control register 1 (CRC1).
This capture/compare register operates as CR11 in the 8-bit operating mode, and CR11W in the 16-bit operating mode.
CR11/CR11W can be read or written to with an 8/16-bit manipulation instruction. The contents of this register are undefined
after RESET input.
(a) When specified as compare register
CR11/CR11W functions as an 8/16-bit register that holds the value that determines the interval timer operation cycle.
An interrupt request (INTC11) is generated by a match between the contents of the CR11/CR11W register and the
contents of TM1/TM1W.
Also, the count value can be cleared by a match. This match signal is also a real-time output port trigger signal.
the read value of the timer register may be illegal. Therefore, do not read the timer register if at all
possible.
If it is necessary to read the timer register, read it two or more times in a row in software, and assume
the value of the timer register is correct only when all the read values match.
CHAPTER 9 TIMER/COUNTER 1
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