CC2745R10-Q1: Setting SPI endian-ness in SimpleLink F3 SDK SPI driver

Colin Howard

Part Number: CC2745R10-Q1

Tool/software:

Hi,

We're using the in-built SPI driver which defaults to MSB first. The device we need to talk to requires LSB first. There is a control bit in the CC2745 to support this. Any suggestions as to the best way to deal with this? I'm trying to avoid "hacking" the driver.

Thanks

Colin

1 month ago

0 Toby 1 month ago

TI__Mastermind 35070 points

Hi Colin,

Yes, there is a control bit in CC2745 to support MSB vs LSB, in the SPI CTL1 register: https://dev.ti.com/tirex/content/simplelink_lowpower_f3_sdk_9_12_00_19/docs/driverlib/cc27xx/register_descriptions/CPU_MMAP/SPI0.html#CTL1

In the SPI TI Driver, by default it configures for MSB: simplelink-lowpower-f3-sdk/source/ti/drivers/spi/SPILPF3DMA.c at main · TexasInstruments/simplelink-lowpower-f3-sdk
However, there is currently no SPI_Param member to set this, so LSB is not possible with the current TI Driver.

Short term, modifying the driver is an option, though understood it may be non-ideal. The modification can be done by copy/pasting the relevant SPI Driver into your project, then modifying it -- one way is to add an extra member in SPI_Params, and another option could be to use the SPI_Param existing "void *custom".

Thanks,
Toby

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CC2745R10-Q1: Setting SPI endian-ness in SimpleLink F3 SDK SPI driver