Sundance Technology
ST201
PRELIMINARY draft 2
TXSTARTTHRESH
Class | I/O Registers, FIFO Control |
Base Address | IoBaseAddress register value |
Address Offset | 0x3c |
Access Mode | Read/Write |
Width | 16 bits |
The value in TxStartThresh is used to control when frames are transmitted. Transmission of a frame begins when the number of bytes for the frame transferred into the TxFIFO is greater than the value in TxStartThresh. If TxStartThresh is set too low, the TxFIFO may experience under run due to the DMA data transfers not able to keep up with the wire data rate. Host systems should use under run indications as a hint to increase the TxStartThresh value. This register resets to 1ffch, which disables the threshold mecha- nism.
BIT
12..0
15..13
BIT NAME
TxStartThresh
Unused
BIT DESCRIPTION
The number of bytes which must be present in the TxFIFO before frame transmission begins. Values will be interpreted using a resolu- tion of 4 bytes (i.e. 0x00, 0x04, 0x08, 0x0c, 0x0f, etc.)
These bits are ignored.
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