MSP430X33X Datasheet, PDF (13/27 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLERS

MSP430x33x
MIXED SIGNAL MICROCONTROLLERS
SLAS163 – FEBRUARY 1998
8-bit timer/counter
The 8-bit interval timer supports three major functions for applications:
D Serial communication or data exchange
D Plus counting or plus accumulation
D Timer
8-bit timer/counter (continued)
The 8-bit timer/counter peripheral includes the following major blocks: an 8-bit Up-Counter with preload register,
an 8-bit Control Register, an Input clock selector, an Edge detection (e.g. Start bit detection for asynchronous
protocols), and an input and output data latch, triggered by the carry-out-signal from the 8-bit counter.
The 8-bit counter counts up with an input clock which is selected by two control bits from the control register.
The four possible clock sources are MCLK, ACLK, the external signal from terminal P0.1, and the signal from
the logical .AND. of MCLK and terminal P0.1.
Two counter inputs (load, enable) control the counter operation. The load input controls load operations. A
write-access to the counter results in loading the content of the preload register into the counter. The software
writes or reads the preload register with all instructions. The preload register acts as a buffer and can be written
immediately after the load of the counter is completed. The enable input enables the count operation. When
the enable signal is set to high, the counter will count-up each time a positive clock edge is applied to the clock
input of the counter.
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