XR16V794_08 EXAR [Exar Corporation], XR16V794_08 Datasheet - Page 26

• Manufacturer Part Number: XR16V794_08
• Description: HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL
• Manufacturer: EXAR [Exar Corporation]

XR16V794
HIGH PERFORMANCE 2.25V TO 3.6V QUAD UART WITH FRACTIONAL BAUD RATE
The first 8 registers are 16550 compatible with EXAR enhanced feature registers located on the upper 8
addresses. The 4 sets of UART configuration registers are decoded using address lines A0 to A3 as shown
below.
3.2
UART CHANNEL CONFIGURATION REGISTERS
A3 A2 A1 A0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
A
DDRESS
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0 0
0 0
0 1
1 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
T
ABLE
RHR - Receive Holding Reg
THR - Transmit Holding Register
DLL - Divisor LSB
DLM - Divisor MSB
DLD - Divisor Fractional Part
IER - Interrupt Enable Reg
ISR - Interrupt Status Reg
FCR - FIFO Control Reg
LCR - Line Control Reg
MCR - Modem Control Reg
LSR - Line Status Reg
reserved
MSR - Modem Status Reg
SPR - Scratch Pad Reg
FCTR
EFR - Enhanced Function Reg
TXCNT - Transmit FIFO Level Counter
TXTRG - Transmit FIFO Trigger Level
RXCNT - Receive FIFO Level Counter
RXTRG - Receive FIFO Trigger Level
Xoff-1 - Xoff Character 1
Xchar
Xoff-2 - Xoff Character 2
reserved
Xon-1 - Xon Character 1
reserved
Xon-2 - Xon Character 2
reserved
11: UART CHANNEL CONFIGURATION REGISTERS.
- Auto RS485 Delay
R
EGISTER
E
16550 C
NHANCED
26
OMPATIBLE
R
EGISTER
R
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
EAD
/W
RITE
Xon,Xoff Rcvd.
C
LCR[7] = 0
LCR[7] = 1
LCR[7] = 1
LCR[7] = 1
LCR[7] = 0
LCR[7] = 0
OMMENTS
Flags
REV. 1.0.1