MC68336/376
TIME PROCESSOR UNIT
MOTOROLA
USER’S MANUAL
Rev. 15 Oct 2000
11-11
11.5.2 New Input Capture/Transition Counter (NITC)
Any channel of the TPU can capture the value of a specified TCR or any specified loca-
tion in parameter RAM upon the occurrence of each transition or specified number of
transitions, and then generate an interrupt request to notify the CPU32. The times of
the most recent two transitions are maintained in parameter RAM. A channel can per-
form input captures continually, or a channel can detect a single transition or specified
number of transitions, ceasing channel activity until reinitialization. After each transi-
tion or specified number of transitions, the channel can generate a link to other
channels.
Refer to TPU programming note New Input Capture/Transition Counter (NITC) TPU
Function (TPUPN08/D) for more information.
11.5.3 Queued Output Match (QOM)
QOM can generate single or multiple output match events from a table of offsets in
parameter RAM. Loop modes allow complex pulse trains to be generated once, a
specified number of times, or continuously. The function can be triggered by a link from
another TPU channel. In addition, the reference time for the sequence of matches can
be obtained from another channel. QOM can generate pulse width modulated wave-
forms, including waveforms with high times of 0% or 100%. QOM also allows a TPU
channel to be used as a discrete output pin.
Refer to TPU programming note Queued Output Match (QOM) TPU Function
(TPUPN01/D) for more information.
11.5.4 Programmable Time Accumulator (PTA)
PTA accumulates a 32-bit sum of the total high time, low time, or period of an input
signal over a programmable number of periods or pulses. The accumulation can start
on a rising or falling edge. After the specified number of periods or pulses, PTA
generates an interrupt request and optionally generates links to other channels.
From one to 255 period measurements can be made and summed with the previous
measurement(s) before the TPU interrupts the CPU32, providing instantaneous or
average frequency measurement capability, and the latest complete accumulation
(over the programmed number of periods).
Refer to TPU programming note Programmable Time Accumulator (PTA) TPU
Function (TPUPN06/D) for more information.
11.5.5 Multichannel Pulse-Width Modulation (MCPWM)
MCPWM generates pulse-width modulated outputs with full 0% to 100% duty cycle
range independent of other TPU activity. This capability requires two TPU channels
plus an external gate for one PWM channel. (A simple one-channel PWM capability is
supported by the QOM function.)
Multiple PWMs generated by MCPWM have two types of high time alignment: edge
aligned and center aligned. Edge aligned mode uses n + 1 TPU channels for n PWMs;