XR16L2751CM EXAR [Exar Corporation], XR16L2751CM Datasheet - Page 37

• Manufacturer Part Number: XR16L2751CM
• Description: 2.25V TO 5.5V DUART WITH 64-BYTE FIFO AND POWERSAVE
• Manufacturer: EXAR [Exar Corporation]

XR16L2751
2.25V TO 5.5V DUART WITH 64-BYTE FIFO AND POWERSAVE
REV. 1.0.0
FCTR[6]: Scratchpad Swap
FCTR[7]: Programmable Trigger Register Select
Enhanced features are enabled or disabled using this register. Bit 0-3 provide single or dual consecutive
character software flow control selection (see
are selected, the double 8-bit words are concatenated into two sequential characters. Caution: note that
whenever changing the TX or RX flow control bits, always reset all bits back to logic 0 (disable) before
programming a new setting.
EFR[3:0]: Software Flow Control Select
Single character and dual sequential characters software flow control is supported. Combinations of software
flow control can be selected by programming these bits.
4.20
Logic 0 = Scratchpad register is selected as general read and write register. ST16C550 compatible mode.
Logic 1 = FIFO Count register (Read-Only), Enhanced Mode Select Register (Write-Only). Number of
characters in transmit or receive FIFO can be read via Scratchpad register when this bit is set. Enhanced
Mode Select Register is selected when it is written into.
Logic 0 = Registers TRG and FC selected for RX.
Logic 1 = Registers TRG and FC selected for TX.
EFR
C
ONT
X
X
X
0
0
1
0
1
1
0
1
0
BIT
Enhanced Feature Register (EFR)
-3
-3
EFR
C
ONT
X
X
X
0
0
0
1
1
0
1
1
0
BIT
-2
-2
T
ABLE
EFR
C
ONT
16: S
X
X
X
X
0
0
1
0
1
1
1
1
BIT
-1
-1
OFTWARE
Table
EFR
C
ONT
16). When the Xon1 and Xon2 and Xoff1 and Xoff2 modes
0
X
X
X
X
0
0
1
1
1
1
1
F
BIT
37
LOW
-0
-0
C
No TX and RX flow control (default and reset)
No transmit flow control
Transmit Xon1, Xoff1
Transmit Xon2, Xoff2
Transmit Xon1 and Xon2, Xoff1 and Xoff2
No receive flow control
Receiver compares Xon1, Xoff1
Receiver compares Xon2, Xoff2
Transmit Xon1, Xoff1
Receiver compares Xon1 or Xon2, Xoff1 or Xoff2
Transmit Xon2, Xoff2
Receiver compares Xon1 or Xon2, Xoff1 or Xoff2
Transmit Xon1 and Xon2, Xoff1 and Xoff2,
Receiver compares Xon1 and Xon2, Xoff1 and Xoff2
No transmit flow control,
Receiver compares Xon1 and Xon2, Xoff1 and Xoff2
ONTROL
T
RANSMIT AND
F
UNCTIONS
R
ECEIVE
S
OFTWARE
áç
áç
áç
áç
F
LOW
C
ONTROL