RL78/G1H CHAPTER 18 RF TRANSCEIVER
R01UH0575EJ0120 Rev. 1.20 Page 552 of 920
Dec 22, 2016
18.4.2 Frame configuration
(1) RF transmission mode
Automatically generates and outputs the transmission frame. Figure 18 - 4 shows the transmission frame
configuration. The frame configurations after the PHR other than those of the mode switch frame and the
mode switch frame change.
Figure 18 - 4 Transmission Frame Configuration
SHR: Synchronization Header PHR: PHY Header
MPDU: MAC Protocol Data Unit SFD: Start of Frame Delimiter
MSDU: MAC Service Data Unit CRC: Cyclic Redundancy Check
<1> Preamble: 4 to 1000 bytes
<2> SFD: 2 bytes or 4 bytes
<3> PHR: 2 bytes
Value varies when it is transmitted by the frame other than the mode switch frame or the mode switch
frame.
• Frames other than the mode switch frame: The value written in the BBTXFLEN register (the length of
MPDU), the CRCBIT value (FCSType), and the DWEN value (Data Whitening)
• Mode switch frame: the value written in the BBTXMODESW register
<4> MPDU: data whose length ranged from the minimum 3 bytes to the maximum 2047 bytes. The data written
in the transmission RAM is output sequentially.
Note that the CR data which is generated in the CRC calculation circuit is automatically added to the last 2
bytes or 4 bytes when the NOCRC bit in the BBTXRXMODE2 register is “0.”
• Frame control: 2 bytes (4 symbols)
- Frame type (bit 2 to 0)
000b: Beacon frame
001b: the data frame
010b: the ACK frame
011b: the MAC command frame
100b to 111b: reserved
- With/without security (bit 3). Transmission pending bit (bit 4)
- ACK request (bit 5), Transmission in the PAN (bit 6)
- Transmission source address mode (bits 10 and 11), Transmission destination address mode (bits 14
and 15)
- Frame version (bits 12, 13)
• Sequence number: 1 byte
• Address information: PADNID and address for transmission destination and source
• MSDU (MAC payload): frame payload
• CRC: 2-byte or 4-byte frame CRC inspection array
PHR
4 to 1000 bytes 2 or 4 bytes 2 bytes 2 bytes 1 byte 0 to 20 bytes 2 or 4 bytes
Other than the
mode switch
Preamble SFD
SFD PHRPHR
PHR
4 to 1000 bytes 2 or 4 bytes 2 bytes
Mode switch
Preamble SFD
SFD PHRPHR
Address
information
Sequence
number
Frame
control
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