4 operation in each mode, Tmp92cz26a – Toshiba H1 Series User Manual
Page 288
TMP92CZ26A
92CZ26A-285
3.12.4 Operation in Each Mode
(1) 8-bit timer mode
Both TMRA0 and TMRA1 can be used independently as 8-bit interval timers.
a. Generating interrupts at a fixed interval (Using TMRA1)
To generate interrupts at constant intervals using TMRA1 (INTTA1), first stop
TMRA1 then set the operation mode, input clock and a cycle to TA01MOD and
TA1REG register respectively. Then, enable the interrupt INTTA1 and start TMRA1
counting.
Example: To generate an INTTA1 interrupt every 20 us at f
c
= 50 MHz, set each register as
follows;
* Clock state
Clcok gear :
1/1
Prescaler of clock gear : 1/2
MSB
LSB
7
6
5
4
3
2
1
0
TA01RUN
← –
X
X
X
–
–
0
–
Stop TMRA1 and clear it to 0.
TA01MOD
← 0 0 X X 0
1
X
X
Select 8-bit timer mode and select
φT1 (0.16 μs at f
C
= 50
MHz) as the input clock.
TA1REG
← 0
1
1
1
1
1
0
1
Set TA1REG to 20
μ
s
÷ φT1 = 125(7DH)
INTETA1
← X 1 0 1 X
–
–
–
Enable INTTA1 and set it to level 5.
TA01RUN
← –
X
X
X
–
1
1
–
Start TMRA1 counting.
X: Don't Care
−: No change
Select the input clock using Table 3.12.2.
Note:
The input clocks for TMRA0 and TMRA1 are different from as follows.
TMRA0: TA0IN input,
φT1, φT4 or φT16.
TMRA1: Match output of TMRA0,
φT1, φT16, and φT256.