"01010 PWM switch-mode power supply, V and I feedback" P2 Smart Pin question(s)

Comments

• evanh Posts: 15,218

  2023-07-29 04:21

  I've used it once so far. Not for any switchmode function though. It's the only smartpin mode that has both input and output components and as such I was able to make it perform a conditional clock function - https://forums.parallax.com/discussion/comment/1552342/#Comment_1552342

      _pinstart( PIN_CLK, P_PWM_SMPS | P_OE | P_INVERT_OUTPUT |    // SD clock gen smartpin
                  (PIN_CMD - PIN_CLK & 7)<<28 | P_INVERT_A |    // smartA input select
                  (PIN_CMD - PIN_CLK & 7)<<24 | P_INVERT_B,    // smartB input select
                  1 | 10<<16, 5 );
  

  It generates an even square wave on its output while its smartB input is high.

  Note the sysclock/10 clock rate. The function needs to terminate the SD clock output within the same SD clock cycle that smartB goes low. There is I/O staging and the smartpin is synchronously clocked itself ... which means it still takes a few sysclock ticks to respond to a changed input. The large divide by 10 is needed for reliable response when sysclock is overclocked in the high 300's MHz.
• ngeneer Posts: 50

  2023-08-01 16:00

  @evanh said:
  I've used it once so far. Not for any switchmode function though. It's the only smartpin mode that has both input and output components

  curious.... thanks for the new idea!