xr16c850im Exar Corporation, xr16c850im Datasheet - Page 25

• Manufacturer Part Number: xr16c850im
• Description: Uart With 128-byte Fifos And Infrared Irda Encoder/decoder
• Manufacturer: Exar Corporation

xr
REV. 2.3.1
The 850 has a set of configuration registers selected by address lines A0, A1 and A2. The 16C550 compatible
registers can be accessed when LCR[7] = 0 and the baud rate generator divisor registers can be accessed
when LCR[7] = 1 and LCR ≠ 0xBF. The enhanced registers are accessible only when LCR = 0xBF. The
complete register set is shown on
3.0 UART INTERNAL REGISTERS
A2,A1,A0 A
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
0
1
1
1
1
0
0 0
0 1
0 0
0 1
0 1
1 0
1 1
0 0
0 1
1 0
1 1
1 1
1 1
0 0
0 1
1 0
0 0
0 1
1 0
1 1
0 0
DDRESSES
RHR - Receive Holding Register
THR - Transmit Holding Register
DLL - Div Latch Low Byte
DLM - Div Latch High Byte
DREV - Device Revision Code
DVID - Device Identification Code
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
Reserved
SPR - Scratch Pad Register
FLVL - TX/RX FIFO Level Counter Register
EMSR - Enhanced Mode Select Register
TRG - TX/RX FIFO Trigger Level Reg
FC - TX/RX FIFO Level Counter Register
FCTR - Feature Control Reg
EFR - Enhanced Function Reg
Xon-1 - Xon Character 1
Xon-2 - Xon Character 2
Xoff-1 - Xoff Character 1
Xoff-2 - Xoff Character 2
T
ABLE
Table 7
7: XR16C850 UART INTERNAL REGISTERS
16C550 C
R
EGISTER
and
E
NHANCED
Table
OMPATIBLE
8.
25
R
EGISTERS
R
EGISTERS
2.97V TO 5.5V UART WITH 128-BYTE FIFO
R
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Read-only
Write-only
Write-only
Write-only
Write-only
Write-only
Write-only
EAD
/W
RITE
LCR[7] = 1, LCR ≠ 0xBF
LCR[7] = 1, LCR ≠ 0xBF
LCR[7] = 0, FCTR[6] = 0
LCR[7] = 0, FCTR[6] = 1
DLL, DLM = 0x00,
LCR = 0xBF
LCR[7] = 0
LCR[7] = 0
LCR[7] = 0
C
OMMENTS
XR16C850