mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 851

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

Figure 16-116 illustrates an example of the RX buffer descriptor process. It shows the
resulting state of the RX buffer descriptors after they receive 10 characters, an idle period,
and five characters (one with a framing error). The example assumes that MRBLR = 8 in the
SMCx parameter RAM.
POINTER
POINTER
POINTER
POINTER
LENGTH
LENGTH
LENGTH
LENGTH
STATUS
STATUS
STATUS
STATUS
RECEIVED BY UART
CHARACTERS
TIME
Figure 16-116. SMCx UART Receive Buffer Descriptor Example
E
0
E
E
E
1
0
0
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
32-BIT BUFFER POINTER
10 CHARS
RECEIVE BD 1
Freescale Semiconductor, Inc.
RECEIVE BD 0
RECEIVE BD 3
RECEIVE BD 2
For More Information On This Product,
XXXX
0004
0008
0002
ID
ID
1
0
ID
0
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
FR
1
LONG IDLE PERIOD
FRAMING ERROR
BYTE 4 HAS
IDLE TIMEOUT
OCCURRED
RECEPTION
PROGRESS
WITH THIS
BUFFER
STILL IN
BUFFER
FULL
MRBLR = 8 BYTES FOR THIS SMC
Communication Processor Module
STORED UNLESS IDLE
COUNT EXPIRES
BYTE 4 ERROR!
BYTES WILL BE
HAS FRAMING ERROR!
FOURTH CHARACTER
ADDITIONAL
(MAX_IDL)
BUFFER
BUFFER
BUFFER
BYTE 10
BYTE 2
BYTE 3
EMPTY
BYTE 5
BUFFER
BYTE 9
BYTE 1
EMPTY
BYTE 8
BYTE 1
BYTE 2
ETC.
5 CHARS
PRESENT
TIME
8 BYTES
8 BYTES
8 BYTES
8 BYTES
16-399