mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 789

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

16.9.23.2 SCCx ETHERNET RECEIVE BUFFER DESCRIPTOR. The SCCx Ethernet
controller uses the receive (RX) buffer descriptor to report information about the received
data for each buffer. Figure 16-107 illustrates an Ethernet receive buffer descriptor example.
POINTER
POINTER
POINTER
POINTER
STATUS
LENGTH
LENGTH
LENGTH
STATUS
STATUS
LENGTH
STATUS
RECEIVED IN ETHERNET
TIME
TWO FRAMES
E
0
E
E
1
E
1
0
Figure 16-107. Ethernet Receive Buffer Descriptor Example
NON-COLLIDED ETHERNET FRAME 1
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
RECEIVE BD 0
RECEIVE BD 2
RECEIVE BD 1
RECEIVE BD 3
L
1
0
L
Freescale Semiconductor, Inc.
XXXX
0040
0045
XXXX
F
For More Information On This Product,
1
0
F
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
CAUSES BUFFER
CLOSED AFTER
OPTIONAL TAG
APPENDED
RECEIVED.
COLLISION
REUSED
LINE IDLE
BUFFER
TO BE
BUFFER
BYTE
CRC
BUFFER
FULL
EMPTY
STILL
MRBLR = 64 BYTES FOR THIS SCC
COLLIDED FRAME WILL
Communication Processor Module
SOURCE ADDRESS (6)
BE OVERWRITTEN.
OLD DATA FROM
DEST ADDRESS (6)
TYPE/LENGTH (2)
DATA BYTES (50)
FRAME 2
CRC BYTES (4)
TAG BYTE (1)
BUFFER
BUFFER
BUFFER
BUFFER
EMPTY
EMPTY
EMPTY
COLLISION
PRESENT
TIME
64 BYTES
64 BYTES
64 BYTES
64 BYTES
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