Intel 8XC196MC, 8XC196MD, 8XC196MH Programming the EPA and TIMER/COUNTERS, Programming the Timers

EVENT PROCESSOR ARRAY (EPA)

With this method, the resolution of the EPA (selected by the TxCONTROL registers; see Figure 11-8 on page 11-16 and Figure 11-9 on page 11-17) determines the maximum PWM output fre- quency. (Resolution is the minimum time required between consecutive captures or compares.) When the input frequency on XTAL1 is 16 MHz, a 250 ns resolution results in a maximum PWM of 4 MHz.

11.5 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.

11.5.1 Configuring the EPA and Timer/Counter Signals

Before you can use the EPA, you must configure the appropriate port signals 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 (MH Only), 2, 5, and 7 (MD Only)” on page 6-4 for information about configuring the ports.

Table 11-2 on page 11-2 lists the signals associated with the EPA and the timer/counters. Signals that are not being used for an EPA channel or timer/counter can be configured as standard I/O.

11.5.2 Programming the Timers

The control registers for the timers are T1CONTROL (Figure 11-8) and T2CONTROL (Figure 11-9). Write to these registers to configure the timers. Write to the TIMER1 and TIMER2 regis- ters (see Table 11-3 on page 11-3 for addresses) to load a specific timer value.

11-15