Programming The Ethernet Controller; Scc Ethernet Commands - Motorola MPC8260 PowerQUICC II User Manual

Part IV. Communications Processor Module
Table 24-1. SCC Ethernet Parameter RAM Memory Map (Continued)
1
Offset Name
0x9E TADDR_H
0x A0 TADDR_M
0x A2 TADDR_L
1
From SCC base address. See Section 19.3.1, ÒSCC Base Addresses.Ó

24.8 Programming the Ethernet Controller

The core conÞgures the SCC to operate as an Ethernet controller by setting GSMR[MODE]
to 0b1100. Receive and transmit errors are reported through RxBD and TxBD. Several
GSMR Þelds must be programmed to special values for Ethernet. Set DSR[SYN1] to 0x55
and DSR[SYN2] to 0xDE. The 6 bytes of preamble programmed in the GSMR, in
combination with the DSR programming, causes 8 bytes of preamble on transmit
(including the 1-byte start delimiter with the value 0xD5).

24.9 SCC Ethernet Commands

Transmit and receive commands are issued to the CP command register (CPCR).
Table 24-2 describes transmit commands.
Command
When used with the Ethernet controller, this command violates a speciÞc behavior of an Ethernet/IEEE
STOP
802.3 station. It should not be used.
TRANSMIT
Used to ensure that transmission stops smoothly after the current frame Þnishes or has a collision.
GRACEFUL
SCCE[GRA] is set once transmission stops, at which point Ethernet transmit parameters and their BDs
STOP
can be updated. TBPTR points to the next TxBD. Transmission begins once the R bit of the next BD is
TRANSMIT
set and a
RESTART TRANSMIT
Note that if
GRACEFUL STOP TRANSMIT
to the start of the collided frame with the R bit still set in the BD. The frame looks as if it was never sent.
Enables transmission of characters on the transmit channel. The Ethernet controller expects it after a
RESTART
TRANSMIT GRACEFUL STOP TRANSMIT
transmission from the current TBPTR in the channel TxBD table.
Initializes transmit parameters in this serial channel parameter RAM to reset state. Issue only when the
INIT TX
transmitter is disabled.
PARAMETERS
24-10
Width
Hword Allows addition and deletion of addresses from individual and group hash tables.
After placing an address in TADDR, issue a
TADDR_L (temp address low) is the least-signiÞcant half word and TADDR_H
(temp address high) is the most-signiÞcant half word.
Table 24-2. Transmit Commands
command is issued.
is issued and the current frame ends in a collision, TBPTR points
command is issued or a transmitter error. The Ethernet controller resumes
and
INIT TX RX PARAMETERS
MPC8260 PowerQUICC II UserÕs Manual
Description
SET GROUP ADDRESS
Description
resets both transmit and receive parameters.
command.
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