BAT32G1x9 user manual | Chapter 7 Timer A
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Rev.1.02
7.3.3
Timer A counts register 0 (TA0).
This is the 16-bit register. If you write this register, you write the data to the reload register. If you read this
register, you read the count value. The state of reloading registers and counters varies depending on the value of
the TSTART bit of the TARR0 register. For details, please refer to "Rewriting of Registers and Counters in 7.4.1".
The TA0 register is set via the 16-bit memory operation instruction. After generating the reset signal, the value
of the TA0 register changes to "FFFFH".
Figure 7-4 Format of timer A count register 0 (TA0).
Address: 40042300H
reset:
FFFFHR/W
Symbol 15
14
1312 11
10
9876543210
TA0
—
function
Set the scope
bit15
~
0
16-bit counter
Notes
1,
2
0000H~FFFFH
Note 1
If you
write
"1"
to
the
TSTOP
bit
of
the TARR0
register, the count of
the 16-bit
counter
is forcibly stopped
and
the count value becomes
"FFFFH".
2. If
the setting value
of
the TCK2~TCK0
bit of the
TAMR0
register is not
"001B"
(f
CLK
/8) and "011B"
(f
CLK
/2) and
the value of
the TA0
register is
"0000H", which is only oriented immediately after the start of counting DMA
and
EVENTC generate
1
request signal. However,
TAO
and
TAIO
perform alternating outputs.
In event counter mode, regardless of the value
of
the TCK2~TCK0
bit, if the value of
the TA0
register is
"0000H"
, a 1 is generated to the
DMA
and EVENTC
immediately after the start of counting The signal is
requested, and the TAO outputs alternately even if the specified period is not counted.
If the value of the TA0
register is greater than or equal to
"0001H", a
request signal is generated each time the
TA underflow occurs.
Note that when the TA0
register is accessed, the
CPU
does not enter the processing of the next instruction but is in a
waiting state of CPU processing. Therefore, when this wait occurs, the number of clocks executed by the
instruction increases the number of clocks waited. The
number of read and write wait clocks when accessing
the
TA0
register is
1
clock.