XR17V358 Datasheet, PDF (42/68 Pages) Exar Corporation – HIGH PERFORMANCE OCTAL PCI EXPRESS UART

XR17V358
PRELIMINARY
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
REV. P1.0.2
3.5 UART CHANNEL CONFIGURATION REGISTERS
Address lines A0 to A3 select the 16 registers in each channel. The first 8 registers are 16550 compatible with
EXAR enhanced feature registers located on the upper 8 addresses.
TABLE 13: UART CHANNEL CONFIGURATION REGISTERS
ADDRESS
REGISTER
READ/WRITE
COMMENTS
A3 A2 A1 A0
16550 COMPATIBLE
0 0 0 0 RHR - Receive Holding Register
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
Read/Write
LCR[7] = 1
0 0 0 1 IER - Interrupt Enable Register
Read/Write
LCR[7] = 0
0 0 1 0 ISR - Interrupt Status Register
FCR - FIFO Control Register
Read-only
Write-only
LCR[7] = 0
0 0 1 1 LCR - Line Control Register
Read/Write
0 1 0 0 MCR - Modem Control Register
Read/Write
0 1 0 1 LSR - Line Status Register
Read-only
0 1 1 0 MSR - Modem Status Register
- Auto RS485 Delay
Read-only
Write-only
EFR bit-4 = 1
0 1 1 1 SPR - Scratch Pad Register
Read/Write
ENHANCED REGISTER
1 0 0 0 FCTR - Feature Control Register
Read/Write
1 0 0 1 EFR - Enhanced Function Register
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
Write-only
1 1 1 0 Xon-1 - Xon Character 1
Write-only
1 1 1 1 Xon-2 - Xon Character 2
Write-only
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