Sundance Technology
ST201
PRELIMINARY draft 2
TXSTATUS |
|
Class | I/O Registers, Control and Status |
Base Address | IoBaseAddress register value |
Address Offset | 0x46 |
Access Mode | Read (write to advance queue) |
Width | 8 bits |
The TxStatus register returns the status of frame transmission or transmission attempts. TxStatus actually implements a queue of up to 31 transmit status bytes. An I/O write of an arbitrary value to TxStatus will advance the queue to the next transmit status byte.
BIT
0
1
2
3
4
5
6
7
BIT NAME
Reserved
TxReleaseError
TxStatusOverflow
MaxCollisions
TxUnderrun
Reserved
TxIndicateReqd
TxComplete
BIT DESCRIPTION
Reserved for future use. Should be set to 0.
Indicates that a transmit release error occurred, meaning that the frame transmission experienced a collision after the front of the frame had already been released to the TxFIFO free space. Refer to TxRe- leaseThresh register for complete description.
When set, indicates that the TxStatus stack is full and as a result the transmitter has been disabled. Writing TxStatus clears this bit, but the transmitter must be
When set, the frame was not successfully transmitted due to encoun- tering 16 collisions. TxEnable must be set to recover from this condi- tion. The frame is discarded from the TxFIFO, so driver should resubmit the frame for transmission.
This bit indicates that the frame experienced an under run during the transmit process because the host was unable to supply the frame data fast enough to keep up with the network data rate. An under run will halt the transmitter and the TxFIFO. The TxReset and TxEnable bits must be set prior to
Reserved for future use. Should be set to 0.
This bit is asserted if the TxIndicate bit was set when the
If this bit is cleared, then the remainder of the status bits are undefined. If the host chooses to poll this register while waiting for a frame trans- mission to complete, then this bit is used to determine that a frame transmission attempt has either experienced an error, or has com- pleted successfully with the TxIndicate bit set in the TransmitFrame- Control.
57
