MPC8544COMEDEV Freescale Semiconductor, MPC8544COMEDEV Datasheet - Page 907

• Manufacturer Part Number: MPC8544COMEDEV
• Description: KIT DEV EXPRESS MPC8544COM
• Manufacturer: Freescale Semiconductor
• Type: MPUr

Specifications of MPC8544COMEDEV

• Contents: Board
• For Use With/related Products: MPC8544
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The TxBD definition is interpreted by eTSEC hardware as if TxBDs mapped to C data structures in the
manner illustrated by Figure 15-136.
The TxBD fields are detailed in
Freescale Semiconductor
Offset
0–1
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;
Bits
0
1
2
3
4
uint_16 flags;
uint_16 length;
uint_32 bufptr;
MPC8544E PowerQUICC III Integrated Host Processor Family Reference Manual, Rev. 1
PAD/CRC Padding for frames. (Valid only while it is set in the first BD and MACCFG2[PAD enable] is cleared).
Name
Table 15-146. Transmit Data Buffer Descriptor (TxBD) Field Descriptions
W
R
L
I
Ready, written by eTSEC and user.
0 The data buffer associated with this BD is not ready for transmission. The user is free to
1 The data buffer, which is prepared for transmission by the user, was not transmitted or is currently
If MACCFG2[PAD enable] is sector if the eTSEC is operating in FIFO mode (ECTRL[FIFM] is set),
this bit is ignored.
0 Do not add padding to short frames.
1 Add PAD to frames. PAD bytes are inserted until the length of the transmitted frame equals 64
Wrap. Written by user.
0 The next buffer descriptor is found in the consecutive location.
1 The next buffer descriptor is found at the location defined in TBASE.
Interrupt. Written by user.
0 No interrupt is generated after this buffer is serviced.
1 IEVENT[TXB] or IEVENT[TXF] are set after this buffer is
Last in frame. Written by user.
0 The buffer is not the last in the transmit frame.
1 The buffer is the last in the transmit frame.
Figure 15-136. Mapping of TxBDs to a C Data Structure
manipulate this BD or its associated data buffer. The eTSEC clears this bit after the buffer is
transmitted or after an error condition is encountered.
being transmitted. No fields of this BD may be written by the user once this bit is set.
bytes. Unlike the MPC8260 which PADs up to MINFLR value, the eTSEC PADs always up to the
IEEE minimum frame length of 64 bytes. CRC is always appended to frames.
interrupt if they are enabled (That is, IEVENT[TXBEN] or IEVENT[TXFEN] are set).
Table
15-146.
Description
Enhanced Three-Speed Ethernet Controllers
serviced.
These bits can cause an
15-175