CC1200: FIFO error appears even if the IC is configured for Synchronous serial mode

We are checking these flags because the CC1200 enters into FIFO error states and stuck there forever until the FIFO is cleared. 

Also we are not changing between FIFO mode and synchronous serial mode. Still we are getting FIFO errors and IC is not able to communicate until the errors are cleared.

Regards,

Rakshith

Please provide info on what MARCSTATE reports and what flags are set when this occurs.

Also, are you switching between RX and TX without strobing IDLE in-between?

BR

Siri

For instance, when we send SRX strobe, MARC_STATE = 17 (RX_FIFO_ERR). After sending the command sequence SFRX-SIDLE-SRX, MARC_STATE becomes 109(RX);

Let me know which flag states info is needed on above cases.

Regards,

Rakshith

I was just wondering if you were reading marcstate or if you had FIFO error flags output on GPIOs.

When it fails, are you strobing RX from TX or from IDLE?

SIri

Ya, I am reading the MARCSTATE.

Always I am strobing RX from IDLE. The thing is we have implemented a workaround to avoid communication break by using SFRX-SIDLE-SRX sequence. But what we need is to avoid this FIFO error completely since its pretty frequent.

Regards,

Rakshith

Please provide more infomation on what you do in your code and how often it fails.

I have done several tests, both with your settings and the recommended settings for serial mode from SmartRF Studio, and I am not able to reproduce the problem. I am changing mode from RX to TX, from TX to RX, from RX to RX (via IDLE), but are never getting any FIFO errors reported.

My test code is below:

while(TRUE)
{
    // TX
    trxSpiCmdStrobe(CC120X_STX);
    waitMs(50);
    cc120xSpiReadReg(CC120X_MARCSTATE, &marcstate, 1);
    marcstate = marcstate&0x1F;
    if(marcstate != 0x13)
      while(1);
    // TX
    // |
    // RX
    trxSpiCmdStrobe(CC120X_SRX);
    waitMs(5000);
    cc120xSpiReadReg(CC120X_MARCSTATE, &marcstate, 1);
    marcstate = marcstate&0x1F;
    if(marcstate != 0x0D)
      while(1);
    // RX
    // |
    // IDLE
    trxSpiCmdStrobe(CC120X_SIDLE);
    waitMs(5);
    // IDLE
    // |
    // RX
    trxSpiCmdStrobe(CC120X_SRX);
    waitMs(5000);
    cc120xSpiReadReg(CC120X_MARCSTATE, &marcstate, 1);
    marcstate = marcstate&0x1F;
    if(marcstate != 0x0D)
      while(1);
    // RX
    // |
    // IDLE
    trxSpiCmdStrobe(CC120X_SIDLE);
    waitMs(5);
    // IDLE
    // |
    // RX
    trxSpiCmdStrobe(CC120X_SRX);
    waitMs(5000);
    cc120xSpiReadReg(CC120X_MARCSTATE, &marcstate, 1);
    marcstate = marcstate&0x1F;
    if(marcstate != 0x0D)
      while(1);
    // RX
}

BR

Siri

Have you configured the IC in synchronous serial mode?

Regards,

Rakshith

yes. I have tested the code with the setting you posted in the first post, and I have also tested with settings exported from SmartRF Studio in Sync serial mode.

Siri

Apart from given configuration, we are having lot of transmission and reception over RF. Also we are using SPI bit banging implemented. 

Regards,

Rakshith

I guess that if I shall be able to figure out what is going on, I need a way to re-produce the problem. Right now, I am not able to do so with my code, even if I am using your settings.

Can you try to make a simple test code where you only go in and out of RX and or TX, like I did in my test, and see if you see any problems then? Do not send any packets while doing this test.

BR

Siri