TMS320F28035: SPI INT FLAG REGISTER PROBLEM

Andrey Kiselnikov

Part Number: TMS320F28035

Hi everyone, I have the following situation: I put the eight bit character in to SPI TX BUF register and it shifted out (I see it in scope), then i check the SPI INT FLAG in SPI STATUS register, but it dont goes high. What can i do wrong?

ps I attached the scope screen, and spi register cfg to this post.

over 9 years ago

0 Mark Labbato over 9 years ago

Guru 30330 points

Andrey,

The SPISTS.INT_FLAG bit should not be used if the FIFO mode is enabled. As this bit is cleared by a read of SPIRXBUF, the bit is automatically cleared by the SPI. This is because in FIFO mode, SPIRXBUF is read by HW and it's contents moved to the receive FIFO.

You can use the FIFO receive Status bit (SPIFFRX.RXFFST) to achieve the same functionality.

We have already filed a bug for a note describing this behavior to be added to the documentation.

-Mark

0 Andrey Kiselnikov over 9 years ago in reply to Mark Labbato

Prodigy 80 points

Thanks!

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TMS320F28035: SPI INT FLAG REGISTER PROBLEM