Motorola PowerQUICC II MPC8280 Series Reference Manual page 777

E
Status 0
Length
Pointer 32-Bit Buffer Pointer
E
Status 0
Length
Pointer 32-Bit Buffer Pointer
E
Status 0
Length
Pointer 32-Bit Buffer Pointer
E
Status 1
Length
Pointer 32-Bit Buffer Pointer
Stored in Rx Buffer
F A A C
Two Frames
Received in HDLC
Time
Legend:
F = Flag
A = Address byte
C = Control byte
I = Information byte
CR = CRC Byte
Figure 22-5. SCC HDLC Receiving Using RxBDs
MOTOROLA
Freescale Semiconductor, Inc.
Receive BD 0
L F
0 1
0x0008
Receive BD 1
L F
1 0
0x000B
Receive BD 2
L F AB
1 1 1
0x0003
Receive BD 3
XXXX
I I I I I I CR CR F
Chapter 22. SCC HDLC Mode
For More Information On This Product,
Go to: www.freescale.com
SCC HDLC Receive Buffer Descriptor (RxBD)
MRBLR = 8 Bytes for this SCC
Address 1
Address 2
Buffer Full
Control Byte
Information
(I-Field) Bytes
Last I-Field Byte
CRC Byte 1
Buffer Closed
CRC Byte 2
When Closing Flag
Received
Address 1
Address 2
Abort Was
Control Byte
Received After
Control Byte
Buffer
Still Empty
Stored in Rx Buffer
Line Idle F A
Buffer
8 Bytes
5
Buffer
8 Bytes
Empty
Buffer
8 Bytes
Empty
Buffer
8 Bytes
Empty
A C Abort/Idle
Unexpected Abort Present
Occurs Before Time
Closing Flag
22-11