TPS65987D: How can FTDI and TPS65987D use the same SPI interface on the TPS65987DEVM?

Hongpei Liu1

Part Number: TPS65987D

I am trying to use the same way as the tps65987DEVM to program the eeprom with FTDI via SPI. But from the schematic of tps65987DEVM, the SPI of the EEPROM connects to both TPS65987D and FTDI. Then the output signals (like the clk, MISO, spi_ss) of the SPI master would connect directly. Doesn't this short the FTDI and tps65987DEVM SPI output pins? Or it will as high z when it is not used? Please advise.

Thank you,

Jason

over 3 years ago

0 Emma Hoying over 3 years ago

TI__Genius 9630 points

HI Jason,

In this scenario, the TPS65987D and the FTDI are both SPI masters, both with the ability to communicate with the EEPROM (SPI slave). This is not an issue because the TPS65987D only actively drives the SPI lines on boot up and the FTDI will access the EEPROM once after boot for debugging and flashing purposes.

Regards,

Emma

0 Hongpei Liu1 over 3 years ago in reply to Emma Hoying

Prodigy 30 points

Hi Emma,

Thank you for your answer. Do I need to set this in the register or it will always configure like this? I may miss it but I didn't find anywhere explains this in the datasheet. Can you point me where I can find this?

Thank you again,

Jason

0 Emma Hoying over 3 years ago in reply to Hongpei Liu1

TI__Genius 9630 points

Hi Jason,

Once you've programmed the external EEPROM, the PD controller will always look to download the patch from the EEPROM. You do not need to configure anything further. Section 8.3.13 talks about the SPI Master Interface.

Regards,

Emma

0 Hongpei Liu1 over 3 years ago in reply to Emma Hoying

Prodigy 30 points

Got it, thank you.

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TPS65987D: How can FTDI and TPS65987D use the same SPI interface on the TPS65987DEVM?