xr16l2550im Exar Corporation, xr16l2550im Datasheet - Page 20

• Manufacturer Part Number: xr16l2550im
• Description: Industry Smallest Package Uart With 2.25v To 5.5v Operation
• Manufacturer: Exar Corporation

XR16L2550
LOW VOLTAGE DUART WITH 16-BYTE FIFO
Each of the UART channel in the L2550 has its own set of configuration registers selected by address lines A0,
A1 and A2 with CSA# or CSB# selecting the channel. The registers are 16C550 compatible. 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
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 0
0 0
0 1
1 0
1 1
0 0
DDRESSES
T
ABLE
Table 7
RHR - Receive Holding Register
THR - Transmit Holding Register
DLL - Div Latch Low Byte
DLM - Div Latch High Byte
DREV - Device Revision
DVID - Device ID
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
EFR - Enhanced Function Register
Xon-1 - Xon Character 1
Xon-2 - Xon Character 2
Xoff-1 - Xoff Character 1
Xoff-2 - Xoff Character 2
7: UART CHANNEL A AND B UART INTERNAL REGISTERS
and
Table
16C550 C
R
EGISTER
8.
E
NHANCED
OMPATIBLE
20
R
EGISTERS
R
EGISTERS
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/Write
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
Read-only
Write-only
EAD
/W
RITE
DLL = 0x00, DLM = 0x00
LCR[7] = 1, LCR ≠ 0xBF,
LCR[7] = 1, LCR ≠ 0xBF
LCR ≠ 0xBF
LCR ≠ 0xBF
LCR = 0xBF
C
LCR[7] = 0
LCR[7] = 0
OMMENTS
REV. 1.1.2