CHAPTER 7 8-BIT TIMER/EVENT COUNTER
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(1) 8-bit compare registers (CR10, CR20)
This is an 8-bit register to compare the value set to CR10 to the 8-bit timer register 1 (TM1) count value, and
the value set to CR20 to the 8-bit timer register 2 (TM2) count value, and, if they match, generates an interrupt
request (INTTM1 and INTTM2, respectively).
CR10 and CR20 are set with an 8-bit memory manipulation instruction. They cannot be set with a 16-bit
memory manipulation instruction. When the compare register is used as 8-bit timer/event counter, the 00H
to FFH values can be set. When the compare register is used as 16-bit timer/event counter, the 0000H to
FFFFH values can be set.
RESET input makes CR10 and CR20 undefined.
Cautions
1.
When using the compare register as 16-bit timer/event counter, be sure to set data after
stopping timer operation.
If the values after CR10 and CR20 are changed are smaller than those of 8-bit timer
registers (TM1 and TM2), TM1 and TM2 continue counting, overflow and then restart
counting from 0. Thus, if the value after CR10 and CR20 change is smaller than that before
change, it is necessary to restart the timer after changing CR10 and CR20.
2.
(2) 8-bit timer registers 1, 2 (TM1, TM2)
These are 8-bit registers to count count pulses.
When TM1 and TM2 are used in the "two 8-bit timer channels" mode, they should be read with an 8-bit memory
manipulation instruction. When TM1 and TM2 are used in the "one 16-bit timer channel" mode, the 16-bit
timer (TMS) should be read with a 16-bit memory manipulation instruction.
RESET input clears TM1 and TM2 to 00H.
7.3 8-Bit Timer/Event Counter Control Registers
The following four types of registers are used to control the 8-bit timer/event counter.
Timer clock select register 1 (TCL1)
8-bit timer mode control register (TMC1)
8-bit timer output control register (TOC1)
Port mode register 3 (PM3)
(1) Timer clock select register 1 (TCL1)
This register sets count clocks of 8-bit timer registers 1 and 2.
TCL1 is set with an 8-bit memory manipulation instruction.
RESET input clears TCL1 to 00H.