SB16C1054PCI_Data Sheet_EN

SB16C1054PCI
PCI Target Interface Controller
with Quad-UART
JULY 2013 REV 1.04
59
the number of data received in RX FIFO at the first time is
less than the value of FUR, or it means the number of data
in RX FIFO was more than the value of FUR and after the
CPU read them, the number of data that remains unread
after the CPU read the data received in RX FIFO is less
than or equal to the value of FLR. That is, UART transmits
Xon character to report external device that it can receive
more data.
1b: It shows that the number of data received in RX FIFO
exceeds the value of FUR and transmitting Xoff character to
report external device that it cannot receive more data. If
RX FIFO has space to store more data, new data are stored
in RX FIFO but after it gets full, they are lost.
For more details, refer to ‘12.3 Software Flow Control’.
3:2
FSR[3:2]
Not used, always 00b.
1
FSR[1]
RX Hardware Flow Control Status:
0b: When FIFO or Auto-CTS flow control is disabled.
If FIFO and Auto-CTS flow control is enabled, 0b is inputted
in CTS# pin and it means external device can receive more
data. This time data in TX FIFO are transmitted.
1b: If FIFO and Auto-CTS flow control is enabled, 1b is inputted
in CTS# pin and it means external device can not receive
more data. This time data in TX FIFO are not transmitted.
For more details, refer to ‘12.2 Hardware Flow Control’.
0
FSR[0]
RX Software Flow Control Status:
0b: When FIFO or RX Software flow control is disabled.
If FIFO and RX Software flow control is enabled, it means
Xoff character has never arrived or Xon character arrived
after Xoff character had arrived(it means external device
can receive more data). This time data in TX FIFO are
transmitted.
1b: If FIFO and RX Software flow control is enabled, it means
Xoff character has arrived and external device can not
receive data any more. This time characters in TX FIFO are
not transmitted.
For more details, refer to ‘12.3 Software Flow Control’.