TMS570LS04x SPI chip select: values of spiDAT1_t.CSNR

Jan Cumps

Guru 15740 points

Other Parts Discussed in Thread: HALCOGEN

I'm unsure on what values to set in the spiDAT1_t.CSNR to uniquely set either CS0, 1, 2 or 3.

Is it correct that

- spiDAT1_t.CSNR = 0XFE => CS0 (11111110)

- spiDAT1_t.CSNR = 0XFD => CS1 (11111101)

- spiDAT1_t.CSNR = 0XFB => CS2 (11111011)

- spiDAT1_t.CSNR = 0XF7 => CS3 (11110111)

or am I mixing Encoded Chip Select and normal chip select?

(I'm reading the reference manual Rev A)

over 11 years ago

0 Jan Cumps over 11 years ago

Guru 15740 points

Answering my own question (after creating a testbed and checking with a logic analyzer): yes.

0 Jan Cumps over 11 years ago in reply to Jan Cumps

Guru 15740 points

I could also have done a better job at reading the HALCogen help.

This is what you get when you navigate to Files -> File List -> include -> spi.h -> spiChipSelect

enum spiChipSelect {
SPI_CS_NONE = 0xFFU, SPI_CS_0 = 0xFEU, SPI_CS_1 = 0xFDU, SPI_CS_2 = 0xFBU,
SPI_CS_3 = 0xF7U, SPI_CS_4 = 0xEFU, SPI_CS_5 = 0xDFU, SPI_CS_6 = 0xBFU,
SPI_CS_7 = 0x7FU
}

0 Anthony F. Seely over 10 years ago in reply to Jan Cumps

TI__Guru 68920 points

Thanks for this post Jan,

Actually there was another post on this subject last week that looks to be a good use case for the encoded chip select: e2e.ti.com/.../442349

Best Regards,
Anthony

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TMS570LS04x SPI chip select: values of spiDAT1_t.CSNR