Accessing variable starting points in an array with DMA | Cypress Semiconductor
Accessing variable starting points in an array with DMA
Hello my PSoC heros!
A series of 11 arrays with 4000 bytes each filled by DMA_1 with chained TDs as a circular buffer of 8bit audio samples from an ADC_DelSig (44ksps).
DMA_2 is configured as a chain of TDs (advanced by the same ADC_DelSig EOC) to transfer a new byte from the circular buffer to a VDAC but with an offset starting point to cause a delayed output.
The goal is to control this offset with a variable to change the delay time.
I've almost wrapped my head around how to change DMA_2's starting TD with a variable giving 10 or 11 different delay times. In the meantime priority is given to DMA_1 to avoid conflicts, although I think there's a way to track this with a counter/status register or something.
My question: is there a way, using DMA, to vary the starting TD and the byte in that particular source with a variable?
(I have the variable obtained and scaled via SAR_ADC and a potentiometer.)
Thank you in advance for any wisdom you may offer and the time to articulate it!!! I've been reading your posts for months and really appreciate your guidance and ideas.