CHAPTER 7 8-BIT TIMER/EVENT COUNTER
166
User’s Manual U11302EJ4V0UM
7.5 8-Bit Timer/Event Counter Operating Precautions
(1) Timer start error
An error of up to one clock may occur in the time required for a match signal to be generated after timer
start. This is because 8-bit timer registers 1 and 2 (TM1 and TM2) are started asynchronously to the count
pulse.
Figure 7-14. 8-Bit Timer Register Start Timing
(2) 8-bit compare registers 1 and 2 settings
The 8-bit compare registers (CR10 and CR20) can be set to 00H.
Thus, when an 8-bit compare register is used as an event counter, a one-pulse count operation can be
carried out.
When the 8-bit compare registers are used as a 16-bit timer/event counter, write data to CR10 and CR20
after setting bit 0 (TCE1) of the 8-bit timer mode control register (TMC1) to 0 and stopping timer operation.
Figure 7-15. External Event Counter Operation Timing
Count pulse
TM1, TM2 count value
00H
Timer start
01H
02H
03H
04H
TI1, TI2 input
CR10, CR20
TM1, TM2 count value
00H
00H
00H
00H
00H
TO1, TO2
Interrupt request signal
Содержание mPD780204
Страница 2: ...2 User s Manual U11302EJ4V0UM MEMO ...