Intel 8XC196NT, User Manual

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10-17
EVENT PROCESSOR ARRAY (EPA)
With this method, the resolution of the EPA (selected by the TxCONTROL registers; see Figure
10-8 on page 10-18 and Figure 10-9 on page 10-19) determines the maximum PWM output fre-
quency. (Resolution is the minimum time required between a capture or compare.) At 20 MHz,
a 200 ns resolution results in a maximum PWM of 5 MHz.
10.5 PROGRAMMING THE EPA AND TIMER/COUNTERS
This section discusses configuring the port pins for the EPA and the timer/counters; describes
how to program the timers, the capture/compare channels, and the compare-only channels; and
explains how to enable the EPA interrupts.
10.5.1 Configuring the EPA and Timer/Counter Port Pins
Before you can use the EPA, you must configure the pins of port 1 and port 6 to serve as the spe-
cial-function signals for the EPA and, optionally, for the timer/counter clock source and direction
control signals. See “Bidirectional Ports 1, 2, 5, and 6” on page 6-3 for information about config-
uring the port pins.
NOTE
If you use T2CLK as the timer 2 input clock, you cannot use EPA
capture/compare channel 0. If you use T2DIR as the timer 2 direction-control
source, you cannot use EPA capture/compare channel 1.
Table 10-1 on page 10-3 lists the pins associated with the EPA and the timer/counters. Pins that
are not being used for an EPA channel or timer/counter can be configured as standard I/O.
10.5.2 Programming the Timers
The control registers for the timers are T1CONTROL (Figure 10-8) and T2CONTROL (Figure
10-9). Write to these registers to configure the timers. Write to the TIMER1 and TIMER2 regis-
ters (see Table 10-2 on page 10-3 for addresses) to load a specific timer value.