XR16C2850 Datasheet, PDF (19/43 Pages) Exar Corporation – 3.3V AND 5V DUART WITH 128-BYTE FIFO

XR16C2850
REV. 2.0.0
3.3V AND 5V DUART WITH 128-BYTE FIFO
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TABLE 8: INTERNAL REGISTERS DESCRIPTION. SHADED BITS ARE ENABLED WHEN EFR BIT-4=1
ADDRESS REG READ/
A2-A0 NAME WRITE
BIT-7
BIT-6
BIT-5
BIT-4
BIT-3 BIT-2 BIT-1 BIT-0 COMMENT
16C550 Compatible Registers
0 0 0 RHR RD Bit-7 Bit-6 Bit-5 Bit-4
Bit-3 Bit-2 Bit-1 Bit-0
0 0 0 THR WR Bit-7 Bit-6 Bit-5 Bit-4
Bit-3 Bit-2 Bit-1 Bit-0
001
010
IER RD/WR 0/
0/
0/
0/
Modem RX Line TX RX Data
CTS# Int. RTS# Int. Xoff Int..
Enable Enable Enable
Sleep
Mode
Enable
Status Int. Status- Empty Int.
Enable Int.
Int. Enable
Enable Enable
ISR RD FIFOs FIFOs
0/
0/
INT
INT
INT
INT ^{LCR[7] = 0}
Enabled Enabled
INT
INT
Source Source
Source Source Source Source
Bit-3 Bit-2 Bit-1 Bit-0
Bit-5 Bit-4
010
FCR
WR RXFIFO RXFIFO 0/
0/
Trigger Trigger
TX FIFO TX FIFO
Trigger Trigger
DMA
Mode
Enable
TX
RX FIFOs
FIFO FIFO Enable
Reset Reset
011
LCR RD/WR Divisor Set TX Set
Enable Break Parity
Even
Parity
Parity
Enable
Stop
Bits
Word Word
Length Length
Bit-1 Bit-0
100
MCR
RD/WR 0/
0/
0/ Internal OP2#/INT Rsvd RTS# DTR#
Lopback Output (OP1#) Output Output
BRG IR Mode XonAny _{Enable Enable}
Control Control
Prescaler ENable
1 0 1 LSR RD RX FIFO THR & THR RX Break RX Fram- RX
RX RX Data
Global TSR Empty
ing Error Parity Over- Ready ^{LCR[7] = 0}
Error Empty
Error run
Error
1 1 0 MSR RD
CD# RI# Input DSR# CTS# Delta CD# Delta Delta Delta
Input
Input Input
RI# DSR# CTS#
1 1 1 SPR RD/WR Bit-7 Bit-6 Bit-5 Bit-4
Bit-3
Bit-2 Bit-1 Bit-0 LCR[7] = 0
FCTR[6]=0
1 1 1 EMSR WR
Rsvd
Rsvd
Auto
RTS
Hyst.
bit-3
Auto
RTS
Hyst.
bit-2
Rsvd
Rsvd
Rx/Tx
FIFO
Count
Rx/Tx
FIFO
Count
LCR[7] = 0
FCTR[6]=1
1 1 1 FLVL RD Bit-7 Bit-6 Bit-5 Bit-4
Bit-3 Bit-2 Bit-1 Bit-0
Baud Rate Generator Divisor
000
001
DLL RD/WR Bit-7
DLM RD/WR Bit-7
Bit-6
Bit-6
Bit-5
Bit-5
Bit-4
Bit-4
Bit-3
Bit-3
Bit-2
Bit-2
Bit-1
Bit-1
Bit-0 LCR[7] = 1
LCR ≠ 0xBF
Bit-0
0 0 0 DREV RD
0 0 1 DVID RD
Bit-7
0
Bit-6
0
Bit-5
0
Bit-4
1
Bit-3
0
Bit-2
0
Bit-1
1
Bit-0
0
LCR[7] = 1
LCR ≠ 0xBF
DLL=0x00
DLM=0x00
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