Multiple DMA reads with Termination

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Feature
Clarity
Needs clarification
Activity status
Stale
Tech stack
c
Domain
embedded-iot

Research direction

The issue names pioLib, pio_sm_config_xfer, pio_sm_xfer_data_rx, DMA, and PIO state-machine IRQs, but no source files or tests. Start by locating those transfer APIs and their DMA/IRQ handling, then determine the supported termination behavior for variable-length RX transfers and what documentation or API change would define completion.

Written by the indexing model from the issue text.

Description

I'm trying to use pioLib interface to receive variable length packets, using DMA. The protocol has CLK, 2 data pins and a frame sync. The issue I'm trying to understand is how to terminate the DMA FIFO read?

For example:
pio_sm_config_xfer(pio, sm, PIO_DIR_FROM_SM, 4096, 10));
//This would return number of RX bytes received
pio_sm_xfer_data_rx(static int rp1_pio_sm_xfer_data(PIO pio, uint sm, uint dir, uint data_bytes, void *data, uint &rxBytes);

in the PIO state machine, issue an IRQ terminate the DMA?

Dominant language
C
Stars
346
Forks
98
PR merge metrics
No merged PRs in 30d

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