MSP430G2230: how to generate high speed PWM and change phase on the fly

Hello Carlo,

While changing the phase between the two PWM signals is definitely possible, changing the phase on the fly may not be entirely possible. According to Section 12.2.1 16-Bit Timer Counter in the MSP430x2xx User's Guide, "it is recommended to stop the timer before modifying its operation (with exception of the interrupt enable, and interrupt flag) to avoid errant operating conditions".

However, Section 5.4 Generating Variable Out-of-Phase PWM Signals in the Using the MSP430 Timer_D Module in Hi-Resolution Mode app note mentions "variable-phase-shift PWM pair generation is also achievable with Timer_A and Timer_B; however, the phase shift resolution of Timer_D is much higher. For Timer_D, the generation of two 50%-duty cycle PWM signals with a relative phase shift from 0° to 180° is possible with a maximum resolution of 4ns". Please read through this section and the other sections of the app note carefully.

For a fixed phase of 180 degrees between two PWMs, you can follow Clemens' helpful advice above and in the thread below.

Two pwm signal with 180 degree phase shift USING msp430g2553

Regards,

James