MC68181 Datasheet, PDF (66/119 Pages) Freescale Semiconductor, Inc – Advance Information ROAMING FLEX chip SIGNAL PROCESSOR

MC68181
Freescale Semiconductor, Inc.
Decoder-to-Host Packet Map
DECODER-TO-HOST PACKET MAP
The following table describes the packet ID’s for all of the packets that can be sent to
the host from the FLEX chip IC.
Table B-2 Decoder-to-Host Packet ID Map
Packet ID
(Hexadecimal)
Packet Type
00
01
02–57
58–5F
60
61–7D
7E
7F
80–FE
FF
Block Information Word
Address
Vector or Message (ID is word number in frame)
Reserved
Roaming Status Packet
Reserved
Receiver Shutdown
Status
Reserved
Part ID
HOST-TO-DECODER PACKET DESCRIPTIONS
The following sections describe the packets of information sent from the host to the
FLEX chip IC. In all cases the packets should be sent MSB first (Bit 7 of byte 3 = Bit 31
of the packet = MSB).
Checksum Packet
The Checksum Packet is used to ensure proper communication between the host and
the FLEX chip IC. The FLEX chip IC exclusive-ORs the 24 data bits of every packet it
receives (except the Checksum Packet and the special packet ID’s $1C through $1F)
with an internal checksum register. Upon reset and whenever the host writes a packet
to the FLEX chip IC, the FLEX chip IC is disabled from sending any information to
the host processor until the host processor sends a Checksum Packet with the proper
Checksum Value (CV) to the FLEX chip IC. When the FLEX chip IC is disabled in this
way, it prompts the host to read the Part ID Packet. Note that all other operation
B-6
MC68181 Technical Data Sheet
MOTOROLA
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