XR17V358
54
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
REV. 1.0.6
FCR[3]: DMA Mode Select
This bit has no effect since TXRDY and RXRDY pins are not available in this device. It is provided for legacy
software compatibility.
Logic 0 = Set DMA to mode 0 (default).
Logic 1 = Set DMA to mode 1.
FCR[2]: TX FIFO Reset
This bit is only active when FCR bit [0] is active.
Logic 0= No transmit FIFO reset (default).
Logic 1 = Reset the transmit FIFO pointers and FIFO level counter logic (the transmit shift register is not
cleared or altered). This bit will return to a logic 0 after resetting the FIFO.
FCR[1]: RX FIFO Reset
This bit is only active when FCR bit [0] is active.
Logic 0 = No receive
FIFO
reset (default).
Logic 1 = Reset the receive FIFO pointers and FIFO level counter logic (the receive shift register is not
cleared or altered). This bit will return to a logic 0 after resetting the FIFO.
FCR[0]: TX and RX FIFO Enable
Logic 0 = Disable the transmit and receive FIFO (default).
Logic 1 = Enable the transmit and receive FIFOs. This bit must be set to logic 1 when other FCR bits are
written or they will not be programmed.
T
ABLE
16: T
RANSMIT
AND
R
ECEIVE
FIFO T
RIGGER
T
ABLE
AND
L
EVEL
S
ELECTION
T
RIGGER
T
ABLE
FCTR
BIT [7]
FCTR
BIT [6]
FCR
BIT [7]
FCR
BIT [6]
FCR
BIT [5]
FCR
BIT [4]
R
ECEIVE
T
RIGGER
L
EVEL
T
RANSMIT
T
RIGGER
L
EVEL
C
OMPATIBILITY
Table-A
0
0
0
0
1
1
0
1
0
1
0
0
1 (default)
4
8
14
1 (default)
16C550, 16C2550,
16C2552, 16C554,
16C580, 16L580
Table-B
0
1
0
0
1
1
0
1
0
1
0
0
1
1
0
1
0
1
8
16
24
28
16
8
24
30
16C650A, 16L651