Freescale Semiconductor MCF5329 Reference Manual page 620

Synchronous Serial Interface (SSI)
Field
31–28 Receive FIFO counter 1. Indicates the number of data words in receive FIFO 1.
RFCNT1 0000 0 data words in receive FIFO.
...
1000 8 data words in receive FIFO.
Else Reserved.
27–24 Transmit FIFO counter 1. Indicates the number of data words in transmit FIFO 1.
TFCNT1 0000 0 data words in transmit FIFO.
...
1000 8 data words in transmit FIFO.
Else Reserved.
23–20 Receive FIFO full watermark 1. Controls threshold for when the SSI_ISR[RFF1] flag is set. RFF1 is set when the
RFWM1 data level in Rx FIFO 1 reaches the selected threshold.
0001 RFF1 set when at least one data word has been written to the receive FIFO (RFCNT equals 0x1 – 0x8)
...
1000 RFF1 set when 8 data words have been written to the receive FIFO (RFCNT equals 0x8)
Else Reserved.
19–16 Transmit FIFO empty watermark 1. Controls the threshold at which the SSI_ISR[TFE1] flag is set. The TFE1 flag is
TFWM1 set when the data level in Tx FIFO 1 falls below the selected threshold.
0001 TFE1 set when there are greater than or equal to one empty slots in the Tx FIFO (TFCNT equals 0x0 – 0x7)
...
1000 TFE1 set when there are eight empty slots in the transmit FIFO (TFCNT equals 0x0)
15–12 Receive FIFO counter 0. Indicates the number of data words in receive FIFO 0. See RFCNT1 for bit settings.
RFCNT0
11–8 Transmit FIFO counter 0. Indicates the number of data words in transmit FIFO 0. See TFCNT1 for bit settings.
TFCNT0
7–4 Receive FIFO full watermark 0. Controls threshold for when the SSI_ISR[RFF0] flag is set. RFF0 is set when the
RFWM0 data level in Rx FIFO 0 reaches the selected threshold. See RFWM1 for bit settings.
3–0 Transmit FIFO empty watermark 0. Controls the threshold for when the SSI_ISR[TFE0] flag is set. TFE0 is set when
TFWM0 the data level in Tx FIFO 0 falls below the selected threshold. See TFWM1 for bit settings.
24-26
Table 24-13. SSI_FCSR Field Descriptions
Description
MCF5329 Reference Manual, Rev 3
Freescale Semiconductor