XR16C854CV EXAR [Exar Corporation], XR16C854CV Datasheet - Page 4

• Manufacturer Part Number: XR16C854CV
• Description: 2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
• Manufacturer: EXAR [Exar Corporation]

Pin Description
XR16C854/854D
2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
PIN DESCRIPTIONS
DATA BUS INTERFACE
(R/W#)
(N.C.)
CSC#
N
IOW#
CSA#
(CS#)
CSB#
IOR#
(A3)
(A4)
D7
D6
D5
D4
D3
D2
D1
D0
A2
A1
A0
AME
64-LQFP
P
22
23
24
60
59
58
57
56
55
54
53
40
38
IN
11
9
7
#
68-PLCC
P
32
33
34
68
67
66
52
18
16
20
50
IN
5
4
3
2
1
#
100-QFP
P
37
38
39
95
94
93
92
91
90
89
88
66
15
13
17
64
IN
#
T
I/O
YPE
I
I
I
I
I
I
Address data lines [2:0]. These 3 address lines select one of the
internal registers in UART channel A-D during a data bus transac-
tion.
Data bus lines [7:0] (bidirectional).
When 16/68# pin is at logic 1, the Intel bus interface is selected
and this input becomes read strobe (active low). The falling edge
instigates an internal read cycle and retrieves the data byte from
an internal register pointed by the address lines [A2:A0], puts the
data byte on the data bus to allow the host processor to read it on
the rising edge.
When 16/68# pin is at logic 0, the Motorola bus interface is
selected and this input is not used.
When 16/68# pin is at logic 1, it selects Intel bus interface and this
input becomes write strobe (active low). The falling edge instigates
the internal write cycle and the rising edge transfers the data byte
on the data bus to an internal register pointed by the address lines.
When 16/68# pin is at logic 0, the Motorola bus interface is
selected and this input becomes read (logic 1) and write (logic 0)
signal. Motorola bus interface is not available on the 64 pin pack-
age.
When 16/68# pin is at logic 1, this input is chip select A (active low)
to enable channel A in the device.
When 16/68# pin is at logic 0, this input becomes the chip select
(active low) for the Motorola bus interface.
Motorola bus interface is not available on the 64 pin package.
When 16/68# pin is at logic 1, this input is chip select B (active low)
to enable channel B in the device.
When 16/68# pin is at logic 0, this input becomes address line A3
which is used for channel selection in the Motorola bus interface.
Motorola bus interface is not available on the 64 pin package.
When 16/68# pin is at logic 1, this input is chip select C (active low)
to enable channel C in the device.
When 16/68# pin is at logic 0, this input becomes address line A4
which is used for channel selection in the Motorola bus interface.
Motorola bus interface is not available on the 64 pin package.
4
D
ESCRIPTION
xr
REV. 3.0.1