Software Design
Implementation Notes
DRM028 — Rev 0
Designer Reference Manual
MOTOROLA
Software Design
107
•
The value T2
(e.g.,
T2 = T_Cmt + Per_HlfCmt
) is calculated using
a 16-bit addition with no saturation. So, the time duration up to
65,536
UNIT_PERIOD_T2_US
from actual time (TACNTH,
TACNTL) can be timed at any TACNTH, TACNTL
timer A counter
value.
•
The timer unit
UNIT_PERIOD_T2_US
of timer A is determined by
the MCU bus frequency (8 MHz with 4-MHz oscillator and default
software setting) and timer prescaler set in TASC. So, the default
software value is 2
µ
s. The timer 2 interrupt function is provided by
function
TIMACh3_Int()
.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..
