Manual

RF22
Version: 0.1 Date: 12/23/2008
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Register 33h. Header Control 2
Bit D7 D6 D5 D4 D3 D2 D1 D0
Name Reserved hdlen[2:0] fixpklen synclen[1:0] prealen[8]
Type R R/W R/W R/W R/W
Reset value = 00100010
Bit Name Function
7 Reserved Reserved.
6:4 hdlen[2:0] Transmit/Receive Header Length.
Length of header used if packet handler is enabled for TX/RX (enpactx/rx). Headers are
transmitted/received in descending order.
000: No TX/RX header
001: Header 3
010: Header 3 and 2
011: Header 3 and 2 and 1
100: Header 3 and 2 and 1 and 0
3 fixpklen Fix Transmit/Receive Packet Length.
When fixpklen = 1 the packet length (pklen[7:0]) is not included in the header. When fixpklen = 0
the packet length is included in the header.
2:1 synclen[1:0] Synchronization Word Length.
The value in this register corresponds to the number of bytes used in the Synchronization Word.
The synchronization word bytes are transmitted in descending order.
00: Synchronization Word 3
01: Synchronization Word 3 and 2
10: Synchronization Word 3 and 2 and 1
11: Synchronization Word 3 and 2 and 1 and 0
0 prealen[8] MSB of Preamble Length.
See register Preamble Length.
Register 34h. Preamble Length
Bit D7 D6 D5 D4 D3 D2 D1 D0
Name prealen[7:0]
Type R/W
Reset value = 00001000
Bit Name Function
7:0 prealen[7:0] Preamble Length.
The value in the prealen[8:0] register corresponds to the number of nibbles (4 bits) in the packet.
For example prealen[8:0] = ‘000001000’ corresponds to a preamble length of 32 bits (8*4bits) or 4
bytes. The maximum preamble length is prealen[8:0] = 111111111 which corresponds to a 255
bytes Preamble. Writing 0 will have the same result as if writing 1, which will send one single
nibble of preamble.
Register 35h. Preamble Detection Control 1
Bit D7 D6 D5 D4 D3 D2 D1 D0
Name preath[4:0] SPARE
Type R/W R/W
Reset value = 00100000
Bit Name Function
7:3 preath[4:0] Number of nibbles processed during detection.
2:0 SPARE SPARE bits.