Chapter 12: 10/100 IEEE802.3 Media Access Controller
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
12-41
Word 0 Fields
Bit(s)
Field
Description
full-duplex.
11
TxDefer
Deferred
When set, indicates the frame transmission was delayed because of a deferral. This bit is
set when a frame is transmitted with a collision and the standard backoff is selected in the
configuration register. This bit is not valid while the port is configured for full-duplex.
10
TxSCol
Single Collision
When set, indicates that the frame being transmitted collided only once and was then
transmitted successfully on the Ethernet.
9
TxMCol
Multiple Collisions
When set, indicates that the frame being transmitted collided more than once and was then
transmitted successfully on the Ethernet.
8
TxExCol
Collision Error
When set, indicates that the frame transmission was aborted because of too many
collisions. The number of collision retries allowed is specified in the transmit frame
configuration register.
7
TxLCol
Late Collision
When set, indicates that a transmission is aborted due to a collision occurring later than 512
bit times.
6
TxLCar
Loss of Carrier
When set, indicates the CRS input is Low during the transmission of a frame.
5
SQE
Signal Quality Error Missed
When set, indicates that the SQE test on the macxCOL signal line is not detected at the end
of a transmission.
4
TxUndf
Transmit Underflow
When set, indicates that the TxFIFO had an underflow condition during the frame
transmission. The transmission process is suspended.
3
–
Reserved
2
TxNoBuf
Transmit Buffer Unavailable
When set, indicates that the next Descriptor in the transmit list is owned by the host and
cannot be acquired by the MAC. The transmission process is suspended.
1
TxPStop
Transmit Process Stopped
When set, indicates that the transmit process has stopped.
0
TxGOOD
Good Frame
When set, indicates that a frame transmission was completed without error. This bit will be
set regardless of the state of SQE, TxSCol, TxMCol and TxDefer. This bit will not be set
when TxLCol, TxExDefer, TxExCol or TxUndf
Word 1 Fields
Bit(s)
Field
Description
63:32
Buffer Address 1
This address points to buffer 1 locations. This address must be 8-byte aligned.
31:0
Buffer Address 2
This address points to buffer 2 locations. This address must be 8-byte aligned.
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...