XR16V798 Datasheet, PDF (28/56 Pages) Exar Corporation – HIGH PERFORMANCE 2.25V TO 3.6V OCTAL UART WITH FRACTIONAL BAUD RATE

XR16V798
xr
HIGH PERFORMANCE 2.25V TO 3.6V OCTAL UART WITH FRACTIONAL BAUD RATE
REV. 1.0.0
3.2 UART CHANNEL CONFIGURATION REGISTERS
The first 8 registers are 16550 compatible with EXAR enhanced feature registers located on the upper 8
addresses. The 8 sets of UART configuration registers are decoded using address lines A0 to A3 as shown
below.
TABLE 11: UART CHANNEL CONFIGURATION REGISTERS.
ADDRESS
REGISTER
READ/WRITE
COMMENTS
A3 A2 A1 A0
16550 COMPATIBLE
0 0 0 0 RHR - Receive Holding Reg
THR - Transmit Holding Register
Read-only
Write-only
LCR[7] = 0
0 0 0 0 DLL - Divisor LSB
Read/Write
LCR[7] = 1
0 0 0 1 DLM - Divisor MSB
Read/Write
LCR[7] = 1
0 0 1 0 DLD - Divisor Fractional Part
Read/Write
LCR[7] = 1
0 0 0 1 IER - Interrupt Enable Reg
Read/Write
LCR[7] = 0
0 0 1 0 ISR - Interrupt Status Reg
FCR - FIFO Control Reg
Read-only
Write-only
LCR[7] = 0
0 0 1 1 LCR - Line Control Reg
Read/Write
0 1 0 0 MCR - Modem Control Reg
Read/Write
0 1 0 1 LSR - Line Status Reg
Read-only
0 1 1 0 MSR - Modem Status Reg
- Auto RS485 Delay
Read-only
Write-only
0 1 1 1 SPR - Scratch Pad Reg
Read/Write
ENHANCED REGISTER
1 0 0 0 FCTR
Read/Write
1 0 0 1 EFR - Enhanced Function Reg
Read/Write
1 0 1 0 TXCNT - Transmit FIFO Level Counter
TXTRG - Transmit FIFO Trigger Level
Read-only
Write-only
1 0 1 1 RXCNT - Receive FIFO Level Counter
RXTRG - Receive FIFO Trigger Level
Read-only
Write-only
1 1 0 0 Xoff-1 - Xoff Character 1
Xchar
Write-only
Read-only
Xon,Xoff Rcvd.
Flags
1 1 0 1 Xoff-2 - Xoff Character 2
reserved
Write-only
Read-only
1 1 1 0 Xon-1 - Xon Character 1
reserved
Write-only
Read-only
1 1 1 1 Xon-2 - Xon Character 2
reserved
Write-only
Read-only
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