CC1101: We found that for CC1101 sometimes the GDO0 pin has no action when the data is transmitting. It does not happen frequently. Do you know the possible reasons?

You are not giving any information about what signal you have on GDO0.

Have you checked the MARC state of the chip when the GDO0 does not toggle compared to when it toggles?

the issue is happened only during the transition from Tx and Rx.

 

  Our setting in GDO0 is 0x06 while GDO1 and GDO2 are in default value.

 

  Our software flow on Tx and Rx are the following:

1. Check if Tx/Rx FIFO is overflowed from MARCSTATE. If yes, flush FIFO.
2. Strobe STX/SRX and check if it is in Tx/Rx mode. If not, strobe again.
3. Packet transmission/reception

1. Tx mode: Write the packet to Tx FIFO and wait for rising edge of GDO0 for success transmission indication.
2. Rx mode: Wait for the rising edge of GDO0 for packet reception. Read from Rx FIFO immediately after reception to minimize the chance of overflow.

 

  From our test and observation from GDO0, GDO0 can function properly if it stays on Tx mode/Rx mode. But if we transit from Tx to Rx mode, there is a missing pulse from GDO0 on the last packet transmission while it does not happen if we change from Rx to Tx.

 May I seek your advise about my flow? Thanks.

Not sure if I understand fully: "But if we transit from Tx to Rx mode, there is a missing pulse from GDO0 on the last packet transmission while it does not happen if we change from Rx to Tx."

I assume you wait until you have sent the last packet before you switch state. But in that case you should already have gotten the last pulse on GDO0 before you switch. So when are you switching compared to when you see the last pulse on GDO0?