Correct SPI pins map is in the KeyFob CC2540 reference design or CC2540 chip datasheet?

Younes Rashidi

Other Parts Discussed in Thread: CC2540

Hi TI experts,

I looked at KeyFob CC2540 reference design and it shows SPI MOSI, MISO, SSN and SCK are P0_2, P0_3, P0_4, P0_5 respectively but in the CC2540 chip datasheet (Table 7_1), they are P0_3, P0_2, P0_4, P0_5. It means there is something wrong because MISO and MOSI in the both resources should be in the same places. would you please tell me which one are correct?

Thanks.

over 13 years ago

0 Gijs de Graaf over 13 years ago

Intellectual 415 points

Hello Younes Rashidi,

I've been loopking at the documentation, and the reference design of the keyfob shows the same pins as USART 0 SPI at the top of the table (7-1).

Maybe you have been looking at USART 1 SPI?

Am i wrong?

Best regards,

Gijs

0 Younes Rashidi over 13 years ago in reply to Gijs de Graaf

Intellectual 275 points

Hi Gijs,

Please compare table 7_1 in the datasheet with sheets number 1 and 3 in the Keyfob reference design then you will see the MISO and MOSI are placed in the different pins.

Regards,

0 J Lindh over 13 years ago in reply to Younes Rashidi

TI__Guru 57865 points

Hi Younes,

You are right (Although its 7_1 in the User Guide) and it is the reference design labels that has been written wrong. Rely on the User Guide:

MISO is on P0_2

MOSI is on P0_3

Thanks for pointing out the error.

0 Gijs de Graaf over 13 years ago in reply to J Lindh

Intellectual 415 points

Hello, I just did some measurements and the reference designs labels are indeed wrong, like Nick L said above.

It's so easy to not notice the error :)

Best regards,

Gijs

0 ishnanaveen over 13 years ago in reply to Gijs de Graaf

Prodigy 80 points

I am trying to use SPI in the USART 0 Alt 1 mode. When I configure the appropriate registers, I still don;t see the SPI clock. Has anybody else seen this problem?

0 Leo Bodnar over 13 years ago in reply to ishnanaveen

Intellectual 515 points

Hi,

Are you sending anything via SPI interface while looking for clock pulses? Usually SPI master generates clock only while sending/receiving data and you can't receive without sending something. It can be dummy data if you just need to receive.

Leo

0 ishnanaveen over 13 years ago in reply to Leo Bodnar

Prodigy 80 points

THanks for the reply. I figured what was the mistake. It was pretty elementary actually. Instead of writing to the USART0 buffer, I was writing to USART 1. Now, the USART0 is well and truly working.

0 Tony Megna over 12 years ago in reply to J Lindh

Intellectual 290 points

TI should really get this updated. I followed the reference diagram and just wasted 130 bucks on PCB's because of this typo.

Thanks,

Tony

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Correct SPI pins map is in the KeyFob CC2540 reference design or CC2540 chip datasheet?