xr16c864iq Exar Corporation, xr16c864iq Datasheet - Page 3

• Manufacturer Part Number: xr16c864iq
• Description: Quad Uart With Rx/tx Fifo Counters And 128-byte Fifo
• Manufacturer: Exar Corporation

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REV. 2.0.1
ORDERING INFORMATION
PIN DESCRIPTIONS
Pin Description
DATA BUS INTERFACE
(R/W#)
(N.C.)
CSA#
(CS#)
CSB#
CSC#
N
IOW#
IOR#
(A3)
(A4)
D7
D6
D5
D4
D3
D2
D1
D0
A2
A1
A0
AME
XR16C864CQ
P
XR16C864IQ
ART
N
100-QFP
UMBER
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 channels A-D during a data bus transaction.
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.
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.
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 chan-
nel selection in the Motorola bus interface.
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 chan-
nel selection in the Motorola bus interface.
100-Lead QFP
100-Lead QFP
P
ACKAGE
O
3
PERATING
2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
-40°C to +85°C
0°C to +70°C
D
T
ESCRIPTION
EMPERATURE
R
ANGE
D
EVICE
Active
Active
XR16C864
S
TATUS