Table of Contents
Advertisement
12.4.1
Block Information Word Packet
The Block Information Field is the first field following the synchronization codes of the FLEX
protocol. This field contains information about the frame such as number of addresses and
messages, information about current time, the channel ID, channel attributes, etc. The first block
information word of each phase is used internally to the FLEX decoder and is never transmitted to
the host with the exception of the system collapse which is sent to the host when the FLEX
decoder is in manual collapse mode.
Time block information words 2-4 can be optionally sent to the host by setting the SBI bit in the
control packet (see 12.3.3, Control Packet). All block information words 2-4 can be optionally
sent to the host by setting the ABI bit in the roaming control packet. When the SBI or ABI bit is
set and any block information word 2-4 is received with an uncorrectable number of biterrors, the
FLEX decoder will send the block information word to the host with the e bit setregardless of the
value of the f field in the block information word. The FLEX decoder does not support decoding
of the vector and message words associated with the Data/System Message block info word
(f=101). The ID of a Block Information Word Packet is 0 (decimal).
Table 12-19 Block Information Word Packet Bit Assignments
Bit 7
Bit 6
Byte 3
0
0
Byte 2
e
p
Byte 1
x
x
Byte 0
s
s
7
e: Set if more than 2 bit errors are detected in the word or if the check character calculation fails
after error correction has been performed.
p: Phase on which the block information word was found (0=a, 1=b, 2=c, 3=d)
x: Unused bits. The value of these bits is not guaranteed.
f: Word Format Type. The value of these bits modify the meaning of the s bits in this packet as
described in the BIW word descriptions in the s bit definition below.
s: These are the information bits of the block information word. The definition of these bits
depend on the f bits in this packet. The following table describes the block information words.
Bit 5
1
p
1
0
s
13
s
6
5
Bit 4
Bit 3
0
0
x
x
s
s
12
11
s
s
4
3
Bit 2
Bit 1
0
0
f
f
2
1
s
s
10
9
s
s
2
1
Bit 0
0
f
0
s
8
s
0
359
Advertisement
Table of Contents
