mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 769

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

16.9.22.2 ETHERNET ON THE MPC823. When the MODE field in the general SCCx
mode low register (GSMR_L) selects an SCCx to be in Ethernet mode, the serial
communication controllers perform the full set of IEEE 802.3/Ethernet CSMA/CD media
access control and channel interface functions. In this manual, a serial communication
controller in Ethernet mode is also referred to as an SCCx Ethernet controller.
The SCCx Ethernet controller requires an external serial interface adaptor (SIA) and
transceiver function to complete the interface to the media. This function is implemented in
the Motorola MC68160 enhanced Ethernet serial transceiver (EEST).
The MPC823+EEST solution provides a direct connection to the attachment unit interface
(AUI) or twisted-pair (10BASE-T). The EEST provides a glueless interface to the MPC823,
Manchester encoding and decoding, automatic selection of 10BASE-T versus AUI ports,
10BASE-T polarity detection and correction, LED drivers, and a low-power mode. For more
information, refer to the MC68160 device documentation.
The SCCx Ethernet controller also provides a number of features. Although the MPC823
contains DPLLs that allow Manchester encoding and decoding, these DPLLs were not
designed for Ethernet rates. Therefore, the SCCx Ethernet controller bypasses the on-chip
DPLLs and uses the external system interface adaptor on the EEST instead.
CTSx = CLSN
CDx = RENA
PERIPHERAL BUS
U-BUS
RXDx
RECEIVER
CONTROL
UNIT
Freescale Semiconductor, Inc.
Figure 16-104. Ethernet Block Diagram
For More Information On This Product,
MPC823 REFERENCE MANUAL
RECEIVE
SHIFTER
DATA
FIFO
Go to: www.freescale.com
REGISTERS
CONTROL
TRANSMIT
SHIFTER
DATA
FIFO
TRANSMITTER
CONTROL
UNIT
Communication Processor Module
INTERNAL CLOCKS
TXDx
GENERATOR
AND DEFER
SLOT TIME
COUNTER
CLOCK
RTSx = TENA
CDx = RENA
CTSx = CLSN
RX CLOCK
TX CLOCK
16-317