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6.2 Configuration of 8-Bit Timer/Event Counters 50 to 53
8-bit timer/event counters 50 to 53 consist of the following hardware.
Table 6-1. Configuration of 8-Bit Timer/Event Counters 50 to 53
Item
Timer registers
Registers
Timer outputs
Control registers
(1) 8-bit timer counters 50, 51, 52, and 53 (TM50 to TM53)
TM5n is an 8-bit read-only register that counts the count pulses.
The counter is incremented at the rising edge of the count clock.
TM50 and TM51 or TM52 and TM53 can be cascaded and used as a 16-bit timer.
When TM50 and TM51 are cascaded and used as a 16-bit timer, its value can be read using a 16-bit memory
manipulation instruction. However, because TM50 and TM51 are connected with the internal 8-bit bus, they
are read one at a time. Therefore, read the value of TM50 and TM51 when used as a 16-bit timer two times
for comparison, taking changes in the values during counting into consideration.
When TM52 and TM53 are cascaded and used as a 16-bit timer, its value can be read using a 16-bit memory
manipulation instruction. However, because TM52 and TM53 are connected with the internal 8-bit bus, they
are read one at a time. Therefore, read the value of TM52 and TM53 when used as a 16-bit timer two times
for comparison, taking changes in the values during counting into consideration.
If the count value is read while the timer is operating, stop input of the count clock, and read the count value
at that point. The count value is cleared to 00H in the following cases.
<1> RESET input
<2> Clearing TCE5n
<3> Match between TM5n and CR5n in mode in which the timer is cleared and started on match between
TM5n and CR5n
Caution When TM50 and TM51 or TM52 and TM53 are cascaded, the value of the timer is cleared
to 00H even if the least significant bit (TCE50 or TCE52) of timer mode control register
50 (TMC50) or 52 (TMC52) is cleared.
Remark n = 0 to 3
CHAPTER 6 8-BIT TIMER/EVENT COUNTERS 50 TO 53
8-bit timer counters 50, 51, 52, and 53 (TM50 to TM53)
8-bit compare registers 50, 51, 52, and 53 (CR50 to CR53)
3 lines (TO50 to TO52)
• Timer clock select registers 50, 51, 52, and 53 (TCL50 to TCL53)
• 8-bit timer mode control registers 50, 51, 52, and 53 (TMC50 to TMC53)
User's Manual U15104EJ2V0UD
Configuration
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