
Functional Description and Application Information
Basic Timer Module - TIM (TIM16B4C)
MM912F634
Freescale Semiconductor
140
4.18.4.3
Input Capture
Clearing the I/O (input/output) select bit, IOSn, configures channel n as an input capture channel. The input capture function
captures the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the
timer transfers the value in the timer counter into the timer channel registers, TCn.
The minimum pulse width for the input capture input is greater than two bus clocks.
An input capture on channel n sets the CnF flag. The CnI bit enables the CnF flag to generate interrupt requests.
4.18.4.4
Output Compare
Setting the I/O select bit, IOSn, configures channel n as an output compare channel. The output compare function can generate
a periodic pulse with a programmable polarity, duration, and frequency. When the timer counter reaches the value in the channel
registers of an output compare channel, the timer can set, clear, or toggle the channel pin. An output compare on channel n sets
the CnF flag. The CnI bit enables the CnF flag to generate interrupt requests.
The output mode and level bits, OMn and OLn, select set, clear, toggle on output compare. Clearing both OMn and OLn
disconnects the pin from the output logic.
Setting a force output compare bit, FOCn, causes an output compare on channel n. A forced output compare does not set the
channel flag.
A successful output compare on channel 3 overrides output compares on all other output compare channels. The output compare
3 mask register masks the bits in the output compare 3 data register. The timer counter reset enable bit, TCRE, enables channel
3 output compares to reset the timer counter. A channel 3 output compare can reset the timer counter even if the IOC3 pin is
being used as the pulse accumulator input.
Writing to the timer port bit of an output compare pin does not affect the pin state. The value written is stored in an internal latch.
When the pin becomes available for general-purpose output, the last value written to the bit appears at the pin.
4.18.5
Resets
4.18.5.1
General
details the registers and their bit-fields.
4.18.6
Interrupts
4.18.6.1
General
This section describes interrupts originated by the TIM16B4C block.
Table 186 lists the interrupts generated by the TIM16B4C to
communicate with the MCU.
Table 186. TIM16B4C Interrupts
Interrupt
Offset
Vector
Priority
Source
Description
C[3:0]F
-
Timer Channel 3-0
Active high timer channel interrupts 3-0
TOF
-
Timer Overflow
Timer Overflow interrupt