XR88C681J-F Exar Corporation, XR88C681J-F Datasheet - Page 50

• Manufacturer Part Number: XR88C681J-F
• Description: IC UART CMOS DUAL 44PLCC
• Manufacturer: Exar Corporation
• Type: CMOS Dual Channel UARTr

Specifications of XR88C681J-F

• Number Of Channels: 2, DUART
• Package / Case: 44-LCC (J-Lead)
• Features: *
• Fifo's: 1 Byte, 3 Byte
• Voltage - Supply: 5V
• With Parallel Port: Yes
• With Cmos: Yes
• Mounting Type: Surface Mount
• Data Rate: 1 Mbps
• Supply Voltage (max): 5.25 V
• Supply Voltage (min): 4.75 V
• Supply Current: 15 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 5 V
• Propagation Delay Time Ns: 400 ns
• No. Of Channels: 2
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: PLCC
• No. Of Pins: 44
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1329

D. TIMING CONTROL BLOCK
The Timing Control Block allows to the user to specify the
bit rates that he/she wishes to transmit and receive data at
each channel. The Timing Control Block consists of the
following elements:
D Oscillator Circuit
D Bit Rate Generator
V
cc
Rev. 2.11
MN/
HOLD
-
DT/
DEN
8086 CPU
-
-
R
MX
AD8 - AD15
AD0 - AD7
Figure 23. Schematic of the XR88C681 DUART Device Interfacing to a
M/
-
INTR
INTA
ALE
-
-
RD
WR
-
IO
“Min” Mode 8086 CPU Device
D
C
D
C
74LS373
74LS373
D0 - D7
Q
Q
D8 - D15
50
A8 - A15
D 16 bit Counter/Timer
D 4 - External Input Pins (to clock the Transmitters
D Two Clock Select Registers (32:1 MUXs)
Figure 24 presents a block diagram of the Timing Control
block for the XR88C681 device.
and Receivers, directly)
A4 - A7
-
MEMW
-
MEMR
from higher
priority device
Address
Decoder
A0 - A3
A0 - A3
-
-
-
-
-
IEI
D0 - D7
IACK
RD
WR
CS
INTR
XR88C681