Using chain_to to retrigger DMA1 with DMA2

[kc64]

DMA1 streams waveform data to a PIO state machine which interfaces to a SPI device.
DMA1 reads from a fixed buffer and writes to my spi_sm FIFO.
DMA1 is configured with chain_to=dma2.channel.

DMA2 is intended to write 1 word to the CH1_AL3_READ_ADDR_TRIGGER so that DMA1 restarts from the beginning of the buffer on every cycle. I don't know how to write the .config write parameter to achieve this.

Any suggestions?

Many thanks in advance.

[kc64]

I found my own answer.

dma1.config(
    read=dma1_buffer,
    ...

dma2.config(
    read=id(dma1_buffer),
    ...

[GitHubsSilverBullet]

I found my own answer.

Did you?

#!micropython
# -*- coding: UTF-8 -*-
# vim: fileencoding=utf-8: ts=4: sw=4: expandtab:
from uctypes import addressof

ba = bytearray((0xef,0xbe,0xad,0xde))
print(f'{id(ba):08x} : {machine.mem32[id(ba)]:08x}')
print(f'{addressof(ba):08x} : {machine.mem32[addressof(ba)]&0xffffffff:08x}')

200069b0 : 100407a4
200069c0 : deadbeef

[kc64]

@GitHubsSilverBullet Thank you for your kind and gentle response to my know-it-all solution. I'm very thankful for you and the expertise you bring.