XR16C850CM EXAR [Exar Corporation], XR16C850CM Datasheet - Page 10

• Manufacturer Part Number: XR16C850CM
• Description: 2.97V TO 5.5V UART WITH 128-BYTE FIFO
• Manufacturer: EXAR [Exar Corporation]

XR16C850
2.97V TO 5.5V UART WITH 128-BYTE FIFO
The PC mode interface includes an on-chip address decoder and interrupt selection function for the standard
PC COM 1-4 ports addresses. The selection is made through three input signals: S1, S2 and S3. The selection
summary is shown in
ranging from 0x278 to 0x3FF, it can fit into an embedded applications by offsetting the address lines to the 850.
An example is shown in
Operating in the PC mode eliminates external address decode components.
2.2
SEL#
F
0
0
0
0
0
0
0
0
0
0
IGURE
INPUT
PC MODE
R E S E T
IO R #
T
A E N #
IO W #
IN T
A 1 4
A 1 5
5. PC M
ABLE
D 0
D 1
D 2
D 3
D 4
D 5
D 6
D 7
A 0
A 1
A 2
A 3
A 4
A 5
A 6
A 7
S3, S2, S1
X X X
0 0 0
0 0 1
0 1 0
0 0 0
1 0 0
1 0 1
1 1 0
1 1 1
X X X
I
NPUTS
1: PC M
ODE
E m b e d d e d A p p lica tio n se t to o p e ra te
Table
I
a t a d d re ss 0 x8 0 F 8 to 0 x8 0 F F
Figure 5
ODE
NTERFACE IN AN
A3-A9 A
1. Although the on-chip address decoder was designed for PC applications
I
NTERFACE
O
0x3E8 - 0x3EF
0x3E8 - 0x3EF
0x2E8 - 0x2EF
N
0x3F8 - 0x3FF
0x2F8 - 0x2FF
0x3F8 - 0x3FF
0x2F8 - 0x2FF
0x3F8 - 0x3FF
0x278 - 0x27F
0x378 - 0x37F
-
CHIP
where the UART is operating from 0x80F8 to 0x80FF address space.
DDRESS
D
ECODER
O
E
N
L
MBEDDED
INES TO
-
CHIP
A
DDRESS
10
A
PPLICATION
COM/LPT P
S
D
ELECTION
COM-1
COM-2
COM-3
COM-4
COM-1
COM-2
COM-3
COM-4
LPT-2
LPT-1
G N D
G N D
ECODER AND
V C C
.
ORT
A E N *
R E S E T
A 1
IR Q A
IR Q B
IR Q C
D 0
D 1
D 2
D 3
D 4
D 5
D 6
D 7
A 0
A 2
IO R #
IO W #
A 3
A 4
A 5
A 6
A 7
A 8
A 9
S 3
S 2
S 1
I
NTERRUPT
IRQ O
IRQC (for PC’s IRQ3)
IRQB (for PC’s IRQ4)
IRQB (for PC’s IRQ4)
IRQB (for PC’s IRQ4)
IRQA (for PC’s IRQn)
IRQA (for PC’s IRQn)
IRQA (for PC’s IRQn)
D S R #
D T R #
R T S #
C T S #
O P 1 #
IRQA (for PC’s IRQn
G N D
V C C
C D #
R X
S E L
T X
R I#
S
ELECTION
UTPUT
N/A
N/A
xr
V C C
S
ELECTION
.
REV. 2.3.1