Motorola MPC8260 - Manual (Page 712)

26-16 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
Figure 26-7. RxBD Example
26.3.10 SMC UART TxBD
Data is sent to the CP for transmission on an SMC channel by arranging it in buffers
referenced by the channel TxBD table. Using the BDs, the CP confirms transmission or
indicates error conditions so that the processor knows the buffers have been serviced.
Byte 5
Buffer
0
0008
32-Bit Buffer Pointer
0
E ID
Receive BD 0
Status
Length
Pointer
0
0002
32-Bit Buffer Pointer
1
E ID
Receive BD 1
Status
Length
Pointer
0
0004
32-Bit Buffer Pointer
0
E ID
Receive BD 2
Status
Length
Pointer
1
XXXX
32-Bit Buffer Pointer
E
Receive BD 3
Status
Length
Pointer
Byte 1
Byte 2
Byte 8
Buffer
Byte 9
Byte 10
Buffer
Byte 1
Byte 2
Byte 3
Buffer
Byte 4 Error!
Empty
Additional Bytes
are Stored Unless
Idle Count Expires
(MAX_IDL)
8 Bytes
8 Bytes
8 Bytes
8 Bytes
Characters
Received by UART
Fourth Character
10 Characters
Long Idle Period
has Framing Error!
Present
Time
Time
5 Characters
Buffer Full
Idle Time-Out
Occurred
Byte 4 has
Framing Error
Reception
Still in Progress
with this Buffer
1
FR
etc.
Empty
MRBLR = 8 Bytes for this SMC