Pwm Modes - Intel 8XC196K Series User Manual

Software starts a conversion on channel x. When the conversion is finished and the A/D conver-
sion complete interrupt is generated, the A/D scan mode routine begins. The PTS reads the com-
mand in location 3000H and stores it in a temporary location. Then it increments PTSPTR1 twice
and stores the value of the AD_RESULT register in location 3002H. The final step is to copy the
conversion command from the temporary location to the AD_COMMAND register. The CPU
could process or move the conversion results data from the table before the next conversion com-
pletes and a new PTS cycle begins. When the next cycle begins, PTSPTR1 again points to 3000H
and the repeats the events of the first cycle. The value of the AD_RESULT register is written to
location 3002H and the command at location 3000H is re-executed.
5.6.6

PWM Modes

The PWM toggle and PWM remap modes are designed for use with the event processor array
(EPA) to generate pulse-width modulated (PWM) output signals. These modes can also be used
with an interrupt signal from any other source. The PWM toggle mode uses a single EPA channel
to generate a PWM signal. The PWM remap mode uses two EPA channels, but it can generate
signals with duty cycles closer to 0% or 100% than are possible with the PWM toggle mode. Ta-
ble 5-12 compares the two PWM modes. For code examples, see AP-445, 8XC196KR Peripher-
als: A User's Point of View and "EPA PWM Output Program" on page 10-35.
PWM Toggle Mode
Reads the location specified by PTSPTR1
(usually EPA x _TIME).
Adds one of two values to the location specified by
PTSPTR1. If TBIT is clear, it adds the value in
PTSCONST1. If TBIT is set, it adds the value in
PTSCONST2.
Stores the sum back into the location specified by
PTSPTR1.
Toggles TBIT.
Table 5-11. A/D Scan Mode PTSCB (Example 2)
Unused
Unused
PTSPTR2 (HI) = 1FH
PTSPTR2 (LO) = AAH
PTSPTR1 (HI) = 30H
PTSPTR1 (LO) = 00H
PTSCON = C3H (Mode = 110, UPDT = 0)
PTSCOUNT = 0AH
Table 5-12. Comparison of PWM Modes
STANDARD AND PTS INTERRUPTS
PWM Remap Mode
Reads the location specified by PTSPTR1
(usually EPA x _TIME).
Adds the value in PTSCONST1 to the location
specified by PTSPTR1.
Stores the sum back into the location specified by
PTSPTR1.
Toggles the unused TBIT.
5-31