
Fast Ethernet Controller (FEC)
Freescale Semiconductor
19-29
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
R
TO1
W
TO2
L
TC
ABC
—
—
—
—
—
—
—
—
—
2
Data Length
4
Tx Data Buffer Pointer - A[31:16]
6
Tx Data Buffer Pointer - A[15:0]
Figure 19-26. Transmit Buffer Descriptor (TxBD)
Table 19-30. Transmit Buffer Descriptor Field Definitions
Word
Field
Description
0
15
R
Ready. Written by the FEC and you.
0 The data buffer associated with this BD is not ready for transmission. You are free to manipulate
this BD or its associated data buffer. The FEC clears this bit after the buffer has been transmitted
or after an error condition is encountered.
1 The data buffer, prepared for transmission by you, has not been transmitted or currently transmits.
You may write no fields of this BD after this bit is set.
0
14
TO1
Transmit software ownership. This field is reserved for software use. This read/write bit is not modified
by hardware nor does its value affect hardware.
0
13
W
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 ETDSR.
0
12
TO2
Transmit software ownership. This field is reserved for use by software. This read/write bit is not
modified by hardware nor does its value affect hardware.
0
11
L
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
0
10
TC
Transmit CRC. Written by user (only valid if L is set).
0 End transmission immediately after the last data byte
1 Transmit the CRC sequence after the last data byte
0
9
ABC
Append bad CRC. Written by user (only valid if L is set).
0 No effect
1 Transmit the CRC sequence inverted after the last data byte (regardless of TC value)
0
8–0
Reserved, must be cleared.
2
15–0
Data
Length
Data length, written by user.
Data length is the number of octets the FEC should transmit from this BD’s data buffer. It is never
modified by the FEC.
4
15–0
A[31:16]
Tx data buffer pointer, bits [31:16]
1
1
The transmit buffer pointer, containing the address of the associated data buffer, must always be evenly divisible by 4. The
buffer must reside in memory external to the FEC. This value is never modified by the Ethernet controller.
6
15–0
A[15:0]
Tx data buffer pointer, bits [15:0]
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...