C167CS datasheet(357/517 Pages) INFINEON

357 / 517 page

C167CS

Derivatives

The Pulse Width Modulation Module

User’s Manual

17-16

V2.0, 2000-07

Software Control of the PWM Outputs

In an application the PWM output signals are generally controlled by the PWM module.

However, it may be necessary to influence the level of the PWM output pins via software

either to initialize the system or to react on some extraordinary condition, e.g. a system

fault or an emergency.

Clearing the timer run bit PTRx stops the associated counter and leaves the respective

output at its current level.

The individual PWM channel outputs are controlled by comparators according to the

formula:

PWM output signal = [PTx]

≥ [PWx shadow latch].

So whenever software changes registers PTx, the respective output will reflect the

condition after the change. Loading timer PTx with a value greater than or equal to the

value in PWx immediately sets the respective output, a PTx value below the PWx value

clears the respective output.

By clearing or setting the respective Port 7 output latch the PWM channel signal is driven

directly or inverted to the port pin.

Clearing the enable bit PENx disconnects the PWM channel and switches the respective

port pin to the value in the port output latch.

Note: To prevent further PWM pulses from occurring after such a software intervention

the respective counter must be stopped first.

C167CS Datasheet(PDF) 357 Page - Infineon Technologies AG