XR17D154 Exar Corporation, XR17D154 Datasheet - Page 29

• Manufacturer Part Number: XR17D154
• Description: Four-channel Pci-bus Uart
• Manufacturer: Exar Corporation

XR17D154
UNIVERSAL (3.3V AND 5V) PCI BUS QUAD UART
REV. P1.0.0
Address lines A0 to A3 select the 16 registers in each channel. The first 8 registers are 16550 compatible with
the EXAR enhanced feature registers located on next 8 addresses locations. Addresses 0x080 to 0x093
comprise the Device Configuration Registers and they reside in Channel 0’s space.
.
A3 A2 A1 A0
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
1
1
1
1
0
0
0
0
1
1
1
1
0 1
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
0 0
0 0
1 0
1 1
T
ABLE
RHR - Receive Holding Register
THR - Transmit Holding Register
DLL - Div Latch Low
DLM - Div Latch High
IER - Interrupt Enable Register
ISR - Interrupt Status Register
FCR - FIFO Control Register
LCR - Line Control Register
MCR - Modem Control Register
LSR - Line Status Register
reserved
MSR - Modem Status Register
SPR - Scratch Pad Reg
FCTR
EFR - Enhanced Function Register
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
10: UART CHANNEL CONFIGURATION REGISTERS.
- Auto RS485 Delay
R
EGISTER
E
16550 C
NHANCED
29
OMPATIBLE
R
EGISTER
R
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] = 0
PRELIMINARY
OMMENTS
Flags
áç
áç
áç
áç