MC68181 Datasheet, PDF (29/119 Pages) Freescale Semiconductor, Inc – Advance Information ROAMING FLEX chip SIGNAL PROCESSOR

Freescale Semiconductor, Inc.
APPENDIX A
FLEX OVERVIEW
This appendix gives an overview of the FLEX protocol as it pertains to the Roaming
FLEX chip IC. This is only an overview and in the event that there is contradictory
information, the FLEX Protocol Specification prevails. This overview is derived from
Issue G1.8 of the FLEX Protocol Specification.
FLEX SIGNAL STRUCTURE
As shown in Figure A-1, a FLEX signal is transmitted on a radio channel and consists
of a series of four-minute cycles, each cycle having 128 frames at 1.875 seconds per
frame. A pager may be assigned to process any number of these frames. Any
unassigned frames are not processed, thus reducing power required for signal
processing and extending battery life. If required, however, the pager may
temporarily process more complex information, because individual FLEX cycles can
assign additional frames dynamically using collapse, fragmentation, temporary
addressing, or carry-on information within the FLEX signal.
One Cycle = 4 Minutes
Frame Frame Frame Frame Frame Frame
127
0
1
2
3
4
Frame Frame Frame
125 126 127
One Frame = 1.875 s.
Sync 1 ^Frame Sync 2
Info
Block 0
Word Number
0 to 7
One Block =
160 ms
Block 9
Word Number
72 to 79
Figure A-1 FLEX™ Signal Structure
Block 10
Word Number
80 to 87
AA1226
MOTOROLA
MC68181 Technical Data Sheet
A-1
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