MC68181 Datasheet, PDF (30/119 Pages) Freescale Semiconductor, Inc – Advance Information ROAMING FLEX chip SIGNAL PROCESSOR

MC68181
FLEX Frame Structure
Freescale Semiconductor, Inc.
FLEX FRAME STRUCTURE
As shown in Figure A-1 on page A-1, each FLEX frame consists of:
• Synchronization portion
• Data portion—Eleven data blocks lasting 160 milliseconds each
Frame Synchronization Portion
The synchronization portion consists of:
• First synchronization signal at 1600 bps
• Frame Information Word including:
– Frame Number 0–127 (7 bits)
– Cycle Number 0–14 (4 bits)
• Second synchronization signal at the data rate of the interleaved portion.
FIRST SYNCHRONIZATION SIGNAL
The first synchronization signal is transmitted at 1600 bps and provides a signal to
lock onto the specific frame.
FRAME INFORMATION WORD
The Frame Information Word transmits 11 bits that are divided into a 7-bit frame
number and a 4-bit cycle number. This allows the pager to identify the frame and the
cycle in which it resides uniquely.
SECOND SYNCHRONIZATION SIGNAL
The second synchronization signal indicates the rate at which the data portion is
transmitted, 1600, 3200 or 6400 bits per second.
A-2
MC68181 Technical Data Sheet
MOTOROLA
For More Information On This Product,
Go to: www.freescale.com