Toshiba TLCS-900/H1 Series Manual page 256

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 μs at f
* Clock state
MSB
←
TA01RUN
←
TA01MOD
←
TA1REG
← X
INTETA1
←
TA01RUN
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: Matches output of TMRA0, φT1, φT16, and φT256.
Clcok gear :
Prescaler of clock gear :1/2
LSB
7 6 5 4 3 2 1
– X X X – – 0
0 0 X X 0 1 X
0 1 1 1 1 1 0
1 0 1 X – –
– X X X – 1 1
92CF30-254
= 50 MHz, set each register as follows;
SYS
1/1
0
– Stop TMRA1 and clear it to 0.
Select 8-bit timer mode and select φT1 (0.16 μs at f
X
50 MHz) as the input clock.
Set TA1REG to 20 μs ÷ φT1 = 125(7DH)
1
– Enable INTTA1 and set it to level 5.
– Start TMRA1 counting.
TMP92CF30
=
SYS
2009-06-12