MPC8313CZQADDC Freescale Semiconductor, MPC8313CZQADDC Datasheet - Page 905

• Manufacturer Part Number: MPC8313CZQADDC
• Description: Microprocessors - MPU 8313 REV2.2 PB NO EN EXT
• Manufacturer: Freescale Semiconductor

Specifications of MPC8313CZQADDC

• Processor Series: MPC8313
• Core: e300
• Data Bus Width: 16 bit
• Maximum Clock Frequency: 133 MHz
• Program Memory Size: 16 KB
• Data Ram Size: 16 KB
• Interface Type: I2C
• Mounting Style: SMD/SMT
• Package / Case: PBGA
• Number Of Programmable I/os: 32
• Number Of Timers: 4

The eTSEC clears the R bit in the first word of the BD after it finishes using the data buffer. The transfer
status bits are then updated. Additional transmit frame status can be found in statistic counters in the MIB
block.
Software must expect eTSEC to prefetch multiple TxBDs, and for TCP/IP checksumming an entire frame
must be read from memory before a checksum can be computed. Accordingly, the R bit of the first TxBD
in a frame must not be set until at least one entire frame can be fetched from this TxBD onwards. If eTSEC
prefetches TxBDs and fails to reach a last TxBD (with bit L set), it halts further transmission from the
current TxBD ring and report an underrun error as IEVENT[XFUN]; this indicates that an incomplete
frame was fetched, but remained unprocessed. The relevant TBPTR register points to the next unread
TxBD following the error.
Figure 15-146
The TxBD definition is interpreted by eTSEC hardware as if TxBDs mapped to C data structures in the
manner illustrated by Figure 15-147.
Freescale Semiconductor
Offset + 0
Offset + 2
Offset + 4
Offset + 6
typedef unsigned short uint_16; /* choose 16-bit native type */
typedef unsigned int uint_32; /* choose 32-bit native type */
typedef struct txbd_struct {
} txbd;
R
0
uint_16 flags;
uint_16 length;
uint_32 bufptr;
MPC8313E PowerQUICC™ II Pro Integrated Processor Family Reference Manual, Rev. 2
PAD/CRC
defines the TxBD.
1
W
Figure 15-147. Mapping of TxBDs to a C Data Structure
2
3
I
Figure 15-146. Transmit Buffer Descriptor
L
4
TC
5
PRE/DEF
TX DATA BUFFER POINTER
6
DATA LENGTH
0
7
HFE/LC CF/RL
8
9
Enhanced Three-Speed Ethernet Controllers
10
11
RC
12
13
TOE/UN
14
15-187
TR
15