Motorola MPC823e Reference Manual page 792

Communication Processor Module
IAM—Individual Address Mode
0 = Normal operation. A single 48-bit physical address that is stored in PADDR1_x is
checked when it is received.
1 = The individual hash table is used to check all individual addresses that are
received.
CRC—CRC Selection
00 = Reserved.
01 = Reserved.
10 = 32-bit CCITT-CRC (Ethernet). X32 + X26 + X23 + X22 + X16 + X12 + X11 + X10
+ X8 + X7 + X5 + X4 + X2 + X1 +1. Select this to comply with Ethernet
specifications.
11 = Reserved.
PRO—Promiscuous
0 = Check the destination address of the incoming frames.
1 = Receive the frame regardless of its address.
BRO—Broadcast Address
0 = Receive all frames containing the broadcast address.
1 = Reject all frames containing the broadcast address, unless the PRO bit = 1.
SBT—Stop Backoff Timer
0 = The backoff timer is functioning normally.
1 = The backoff timer for the random wait after a collision is stopped when carrier
sense is active. This method makes the retransmission less aggressive than the
maximum allowed in the IEEE 802.3 standard. The persistence (P_Per) parameter
in the parameter RAM can be used in combination with, or in place of, the SBT bit.
LPB—Loopback Operation
0 = Normal operation.
1 = The channel is configured into internal or external loopback operation as
determined by the DIAG field of the GSMR_L. For external loopback, the DIAG
field must be configured for normal operation and for internal loopback they must
be configured for loopback operation.
Bit 10—Reserved
This bit is reserved and must be set to 0.
LCW—Late Collision Window
0 = A late collision is any collision that occurs at least 64 bytes from the preamble.
1 = A late collision is any collision that occurs at least 56 bytes from the preamble.
16-338 MPC823e REFERENCE MANUAL MOTOROLA