Hello,
I'm building a system around a SoM that features the i.MX 8M Mini. As it's provided to us on a module, I'm needing to be creative about which pins I can use for peripherals.
My goal is for 16 TX channels of TDM data spread across two TX lines (8x on one, 8x on the other that will be sent simultaneously. Eventually targeting something like the AD1934 in daisy-chain mode, but right now I'm just using the "snd-soc-dummy" codec.) My system will need to operate in two distinct modes (not simultaneously -- will depend on board populated hardware): one where the SAI operates as the master, providing MCLK/BCLK/FSYNC
I had initially looked to use SAI2 and SAI3 with one data line each and have them operate in sync with each other. However, according to this post, it seems the RM is erroneous, and the "Synchronous with another SAI xxxx" modes are not supported. This would mean I'd have to route the clocking signals from those two together, which isn't possible given the limitations of my module.
Instead now I'm looking at using both the TXDATA0 and TXDATA1 functions of just SAI2. This appears to be a potential approach, until I realized my only way to get access to the TXDATA1 function on SAI2 was via muxing pad AD23, which is also the SAI2_TXFS function.
My hope is to be able to use the SAI2_RXFS function as my sync clock pad, but I'm unable to determine from the datasheet if it's possible to use the RXFS signal as the source of my clocking (in both of the modes I'll need to support -- generating the clocking externally or generating it internally and outputting it.) I don't mind enabling the RX portion of the module just to get it's clocks, its data pins just won't be muxed to pads.
I appreciate any guidance on this topic!
