• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 99 subscribers
  • Views 276 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

C5505 multiplexing individual pins

Tommy Hosman
Intellectual 260 points

I just wanted to confirm that there is no way to individually control the multiplexing for the parallel pins on the C5505. I am using the EBSR register, but I would like to be able to access SPI_CS0 from the multiplexed LCD_D[9] / I2S2_FS / GPIO[19] / SPI_CS0 in mode 1.

Thanks for any help,

 

Tommy

  • 0
    TI__Mastermind 30140 points

    Hi Tommy,

    You are correct. You cannot bring out SPI_CS0 to LCD_D[9]/I2S2_FS/GP[19]/SPI_CS0 when EBSR PPMODE = 1.

    See SPRS660D - Table 4-4. LCD Controller, SPI, UART, I2S2, I2S3, and GP[31:27, 20:18] Pin Multiplexing.

    Do any of the other modes meet your needs?

    Best Regards,
    Mark

  • 0 in reply to Mark M
    Intellectual 260 points

    Thanks for the quick response Mark.

    No, no other modes meet my needs because I'm using the EZdspC5505 and it does not seem to bring out the other SPI_CS pins besides CS1, which I'm already using. I really need mode 1 with the I2S2_FS pin as SPI_CS0 as that is a pin that is accessible through the EZdspC5505.

     

    If you can think of any other solution, please let me know.

    Thanks,

    Tommy

  • 0 in reply to Tommy Hosman
    TI__Mastermind 30140 points

    Hi Tommy,

    I see your problem. SPI_CS2 & SPI_CS3 are not connected on the C5505 eZdsp...

    But they are brought out to the edge connectors on the C5515 eZdsp and C5535 eZdsp... (Easiest solution)

    One solution is to repurpose the SPI_CS0 (ie blue wire it directly from the SPI EEPROM)

    Maybe you can boot from UART and avoid using the SPI EEPROM that uses SPI_CS0...

    Or maybe you could fool the SPI by accessing SPI_CS2 or SPI_CS3 (not connected) and actually chip selecting your device with a GPIO...

    Hope this helps,
    Mark

  • 0 in reply to Mark M
    Intellectual 260 points

    Thanks Mark,

    Yes, I'm experimenting now with using a GPIO as my new chip select. 

    Thanks for the help.

    Tommy