Motorola M68HC08 - Manual (Page 107)

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
µs. The timer 2 interrupt function is provided by
function TIMACh3_Int().
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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