SPC41A Sunplus Technology Co., Ltd., SPC41A Datasheet - Page 7

• Manufacturer Part Number: SPC41A
• Description: 40KB SOUND CONTROLLER
• Manufacturer: Sunplus Technology Co., Ltd.

6.10. Timer/Counter
The SPC41A contains two 12-bit timer/counters, TMA and TMB
respectively. TMA can be specified as a timer or a counter, but
TMB can only be used as a timer. In the timer mode, TMA and
TMB are re-loaded up-counters.
$0FFF to $0000, the carry signal will make the timer automatically
reload to the user’s pre-set value and be up-counted again. At
the same time, the carry signal will generate the INT signal if the
corresponding bit is enabled in the INT ENABLE Register. If TMA
is specified as a counter, users can reset by loading #0 into the
counter. After the counter has been activated, the value of the
counter can also be read from the counters at the same time.
The read instruction will not affect the value of the counter or reset
it.
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Proprietary & Confidential
When timer overflows from
7
Clock source of Timer/Counter can be selected as follows:
MODE SELECT REGISTER
TIMER CLOCK SELECTOR
TMA
TMB
Timer/Counter
12-BIT TIMER
12-BIT COUNTER
12-BIT TIMER
CPU CLOCK (T) or T/4
T/64, T/8192, T/65536 or EXT
CLK
T or T/4
TMA only, select timer or counter
Select T or T/4
Clock Source
SPC41A
SEP. 04, 2001
Version: 1.8