A N 6 9 2
16
Rev 0.4
Figure 12. Monitor CTS and Read the Response on the SPI Bus
Reading the response from the radio can be interrupted earlier. For example, if the host MCU asked for five bytes
of response, it may read fewer bytes in one SPI transaction. As long as a new command is not sent, the radio
keeps the response for the last request in the command buffer. The host MCU can re-read the response in a new
SPI transaction. In such a case, the response is always provided from the first byte.
Notes:
Up to 16 bytes of response can be read from the radio in one SPI transaction. If more bytes are read, the
radio will provide the same 16 bytes of response in a circular manner.
If the command has N bytes of response, but the host MCU provides less than N bytes of clock pulses
during the read sequence, it causes no issue for the radio. The response buffer is reset if a new command
is issued.
If the command has N bytes of response, but, during the read sequence, the host MCU provides more than
N bytes of clock pulses, the radio will provide unpredictable bytes after the first N bytes. The host MCU
does not need to reset the SPI interface; it happens automatically if NSEL is pulled low before the next
command is sent.
Summary of Contents for Si4455 Series
Page 8: ...AN692 8 Rev 0 4 Figure 6 Device Configuration Options ...
Page 22: ...AN692 22 Rev 0 4 Figure 21 Supply Current versus Time Diagram from Shutdown to RX State ...
Page 23: ...AN692 Rev 0 4 23 4 4 Radio Chip Waking Up Figure 22 Radio Wake Up Process ...
Page 35: ...AN692 Rev 0 4 35 Figure 32 Transmission Flowchart ...
Page 39: ...AN692 Rev 0 4 39 Figure 33 Reception Flowchart ...
Page 41: ...AN692 Rev 0 4 41 Figure 34 Bidirectional Variable Packet Example Project Flowchart ...
Page 47: ...AN692 Rev 0 4 47 Figure 41 Long Packet Transmission Flowchart ...
Page 48: ...AN692 48 Rev 0 4 Figure 42 Long Packet RX Flowchart ...
