Datasheet

Timer Interface Module A (TIMA)
MC68HC908AB32 — Rev. 1.1 Technical Data
Freescale Semiconductor Timer Interface Module A (TIMA)
171
11.4 Pin Name Conventions
The TIMA share five I/O pins with port D, E, and F I/O pins. The full name
of the TIMA I/O pin is listed in Table 11-1. The generic pin name appear
in the text that follows.
11.5 Functional Description
Figure 11-1 shows the structure of the TIMA. The central component of
the TIMA is the 16-bit TIMA counter that can operate as a free-running
counter or a modulo up-counter. The TIMA counter provides the timing
reference for the input capture and output compare functions. The TIMA
counter modulo registers, TAMODH:TAMODL, control the modulo value
of the TIMA counter. Software can read the TIMA counter value at any
time without affecting the counting sequence.
The four TIMA channels are programmable independently as input
capture or output compare channels.
11.5.1 TIMA Counter Prescaler
The TIMA clock source can be one of the seven prescaler outputs or the
TIMA clock pin, PTD6/TACLK. The prescaler generates seven clock
rates from the internal bus clock. The prescaler select bits, PS[2:0], in
the TIMA status and control register select the TIMA clock source.
Table 11-1. Pin Name Conventions
TIMA Generic Pin Names: Full TIMA Pin Names:
TAC LK PT D6/ TACL K
TAC H0 PT E2/TACH0
TAC H1 PT E3/TACH1
TAC H2 PT F0/ TACH 2
TAC H3 PT F1/ TACH 3