Freescale Semiconductor MCF54455 Reference Manual page 697

Synchronous Serial Interface (SSI)
Table 27-13. SSI FIFO Control/Status Register Field Descriptions (continued)
Field
19–16 Transmit FIFO Empty WaterMark 1. These bits control the threshold at which the TFE1 flag will be set.
TFWM1[3:0] The TFE1 flag is set whenever the empty slots in Tx FIFO exceed or are equal to the selected threshold.
Refer to
Bits
0000
0001 TFE set when there are more than or equal to 1 empty slots in Transmit FIFO. (default)
0010 TFE set when there are more than or equal to 2 empty slots in Transmit FIFO.
0011 TFE set when there are more than or equal to 3 empty slots in Transmit FIFO.
0100 TFE set when there are more than or equal to 4 empty slots in Transmit FIFO.
0101 TFE set when there are more than or equal to 5 empty slots in Transmit FIFO.
0110 TFE set when there are more than or equal to 6 empty slots in Transmit FIFO.
0111 TFE set when there are more than or equal to 7 empty slots in Transmit FIFO.
1000 TFE set when there are more than or equal to 8 empty slots in Transmit FIFO.
1001 TFE set when there are more than or equal to 9 empty slots in Transmit FIFO.
1010 TFE set when there are more than or equal to 10 empty slots in Transmit FIFO.
1011 TFE set when there are more than or equal to 11 empty slots in Transmit FIFO.
1100 TFE set when there are more than or equal to 12 empty slots in Transmit FIFO.
1101 TFE set when there are more than or equal to 13 empty slots in Transmit FIFO.
1110 TFE set when there are more than or equal to 14 empty slots in Transmit FIFO.
1111 TFE set when there are 15 empty slots in Transmit FIFO.
27-30
Table 27-17 for details regarding settings for transmit FIFO watermark bits.
Table 27-17. Transmit FIFO WaterMark Bit Description
Transmit FIFO empty is set when TxFIFO <= 14 data.
Transmit FIFO empty is set when TxFIFO <= 13 data.
Transmit FIFO empty is set when TxFIFO <= 12 data.
Transmit FIFO empty is set when TxFIFO <= 11 data.
Transmit FIFO empty is set when TxFIFO <= 10 data.
Transmit FIFO empty is set when TxFIFO <= 9 data.
Transmit FIFO empty is set when TxFIFO <= 8 data.
Transmit FIFO empty is set when TxFIFO <= 7 data.
Transmit FIFO empty is set when TxFIFO <= 6 data.
Transmit FIFO empty is set when TxFIFO <= 5 data.
Transmit FIFO empty is set when TxFIFO <= 4 data.
Transmit FIFO empty is set when TxFIFO <= 3 data.
Transmit FIFO empty is set when TxFIFO <= 2 data.
Transmit FIFO empty is set when TxFIFO <= 1 data.
Transmit FIFO empty is set when TxFIFO = 0 data.
Description
Description
Reserved
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