xr20m1280 Exar Corporation, xr20m1280 Datasheet - Page 29

• Manufacturer Part Number: xr20m1280
• Description: I2c/spi Uart With 128-byte Fifo And Integrated Level Shifters
• Manufacturer: Exar Corporation

A
REV. P1.1.1
A2-A0
DDRESS
0 1 0
1 1 1
1 1 1
0 0 0
0 0 0
0 0 1
0 0 0
0 0 0
0 0 1
0 1 0
1 0 0
1 0 1
1 1 0
1 1 1
1 0 0
1 0 1
1 1 0
1 1 1
T
ABLE
GPIOSEL RD/WR
GPIOINT RD/WR
GPIOINV RD/WR
GPIO3T RD/WR
XOFF1
XOFF2
EMSR
DREV
FCTR
XON1
XON2
N
TRIG
DLM
DLD
EFR
R
DLL
FC
FC
AME
EG
10: INTERNAL REGISTERS DESCRIPTION.
RD/WR
RD/WR
RD/WR
RD/WR
RD/WR
RD/WR
RD/WR
RD/WR
RD/WR
W
R
WR
WR
RD
RD
RD
EAD
RITE
/
interrupt
Enable
RX/TX
Bit-15/
Bit-15/
Bit-15/
Bit-15/
select
select
select
CTS#
mode
B
BRG
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Auto
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Bit-7
Xoff
IT
I2C/SPI UART WITH 128-BYTE FIFO AND INTEGRATED LEVEL SHIFTERS
-7
Indepen-
interrupt
Enable
Enable
Bit-14/
Bit-14/
Bit-14/
Bit-14/
select
mode
Swap
RTS#
B
Bit-6
Bit-6
Bit-6
Bit-6
BRG
Bit-6
Bit-6
SPR
Auto
Bit-6
Bit-6
Bit-6
Bit-6
Bit-6
Bit-6
Bit-6
Bit-6
LSR
dent
IT
-6
Baud Rate Generator Divisor
Enhanced Registers
4X Mode 8X Mode
Special
Trigger
Select
Bit-13/
Bit-13/
Bit-13/
Bit-13/
Table
B
Rsvd
Char
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
bit-1
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
Bit-5
IT
PRELIMINARY
-5
29
MCR[7:5],
FCR[5:3],
IER [7:4],
ISR [5:4],
Modem
3-State
Control
Trigger
Enable
Bit-12/
Bit-12/
Bit-12/
Bit-12/
Table
SHR,
B
DLD,
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
Bit-4
bit-0
SFR
IT
-4
S
HADED BITS ARE ENABLED WHEN
Duplex
RTS in
RS485
RS485
Bit-11/
Bit-11/
Bit-11/
Bit-11/
Invert
mode
B
ware
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Auto
Half-
Soft-
Flow
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Bit-3
Cntl
IT
-3
Bit-10/
Bit-10/
Bit-10/
Bit-10/
imme-
RX IR
invert
B
Send
diate
ware
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Soft-
Flow
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Bit-2
Cntl
TX
IT
-2
control
count
B
Bit-9/
Bit-9/
Bit-9/
Bit-9/
FIFO
Rsvd
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Soft-
ware
Flow
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
Bit-1
bit-1
Cntl
IT
-1
EFR B
PWRDN
control
control
count
XR20M1280
B
FIFO
Bit-8/
Bit-8/
Bit-8/
Bit-8/
ware
Flow
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Soft-
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
Bit-0
bit-0
Cntl
IT
#
-0
IT
-4=1
DLM= 0x00
FCTR[6]=1
LCR=0
LCR=0
LCR=0
LCR≠0xBF
LCR[7] = 1
LCR≠0xBF
DLL= 0x00
LCR[7] = 1
LCR≠0xBF
LCR[7] = 1
LCR≠0xBF
EFR[4] = 1
C
SFR[0]=0
SFR[0]=0
DLD[7:6]
OMMENT
X
X
X
BF
BF
BF