Silicon Laboratories EZRADIOPRO Si4060, Programming Manual

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64 Rev. 0.7
The standard requires the data bytes being sent in an LSB manner, which is taken care of by the radio IC. The
data, i.e., PHR + payload, is being put into the TX FIFO in MSB, but sent over the air in LSB. On the receive side,
the payload is being read out from the RX FIFO in MSB, but the PHR will be in LSB (!). Taking an example from the
standard where 0x40 00 56 is being sent over the air (i.e., 0x02 00 6A in MSB), the four different scenarios are the
following:
1. 3-byte payload, CRC-16, DW disabled
Data to the TX FIFO: | 08 A0 | 02 00 6A | (MSB)
PPDU*: | 55 55 55 55 | 90 4E | 10 05 | 40 00 56 | 27 9E | (LSB transmitted first)
Data from the RX FIFO: | 10 05 | 02 00 6A |
2. 3-byte payload, CRC-16, DW enabled
Data to the TX FIFO: | 18 A0 | 02 00 6A | (MSB)
PPDU*: | 55 55 55 55 | 90 4E | 18 05 | 4F 70 E5 | 48 DD | (LSB transmitted first)
Data from the RX FIFO: | 18 05 | 02 00 6A |
3. 3-byte payload, CRC-32, DW disabled
Data to the TX FIFO: | 00 E0 | 02 00 6A | MSB
PPDU*: | 55 55 55 55 | 90 4E | 00 07 | 40 00 56 | 5D 29 FA 28 | (LSB transmitted first)
Data from the RX FIFO: | 00 07 | 02 00 6A |
4. 3-byte payload, CRC-32, DW enabled
Data to the TX FIFO: | 10 E0 | 02 00 6A | (MSB)
PPDU*: | 55 55 55 55 | 90 4E | 08 07 | 4F 70 E5 | 32 6A 62 60 | (LSB transmitted first)
Data from the RX FIFO: | 08 07 | 02 00 6A |
*Data stream sent over the air. PPDU=SHR + PHR + PSDU.
The preamble pattern is a fixed, 0101 pattern, but can be of any length. The sync word is also fixed, a two-byte,
0x904E pattern (these are the default values in the WDS GUI for the project). The standard allows a maximum of
2047 bytes in length (including the FCS), but the sample code has a limit of 64-bytes. If needed, it can be extended
up to the maximum by using TX FIFO Almost Empty, RX FIFO Almost Full Interrupts. For such long packets,
please refer to Long Packet TX/RX example projects.