I.MX RT1052 PWM update duty cycle Causes inaccurate DMA SPI transmission data

ConnorShang — Tue, 28 Feb 2023 01:47:37 GMT

DMA is used to transmit SPI data. SPI is used as a slave, with a frequency of 21M and 20 bytes per transmission. RT1052 uses 528M as the main frequency. Only SPI uses DMA
Use PWM1 sub-module 0-2 to update the duty cycle every cycle, and use library function to update: PWM_ SetPwmLdok(PWM1,kPWM_Control_Module_0,true);
During use, check SPI data through the host and find that every other period of time, one byte of SPI data will become 0xFF
It is normal to check the data put into the DMA transmission array through debug
Increase the dominant frequency from 528M to 540M, and the number of errors will be reduced. When it is increased to 570M/600M, no errors will occur
Or use 528M main frequency without updating PWM duty cycle
The number of update errors will also decrease when the duty cycle of PWM sub-module is reduced (the more used, the higher the number of errors)
Also tested whether the priority of the DMA channel is changed to high priority or not
The SPI frequency is reduced to 12M, and it is not measured

topic I.MX RT1052 PWM update duty cycle Causes inaccurate DMA SPI transmission data in i.MX RT Crossover MCUs

I.MX RT1052 PWM update duty cycle Causes inaccurate DMA SPI transmission data