XR88C681J-F Exar Corporation, XR88C681J-F Datasheet - Page 75

• 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

In this mode:
1. The transmitter output is internally connected to the
2. The transmit clock is used for the receiver.
3. The channel’s TXDn output is held marking (high).
4. The channel’s RXDn input is ignored.
5. The transmitter is enabled, but the received need not
6. CPU to transmitter and receiver communications
RXDn
receiver input.
be enabled.
continue normally.
Rev. 2.11
Receive Holding
Register
Figure 40. A Block Diagram depicting Local Loopback Mode Operation
Receive Shift Register
(To be read by the CPU)
To Data Bus
8
TXCn
75
Remote Loopback Mode.
This mode is selected by setting MR2n[7:6] = 11.
Figure 41 presents a diagram depicting Remote
Loopback Mode operation.
Transmit Shift Register
(Parallel Data from CPU)
From Data Bus.
8
XR88C681
Transmit Holding
Register
V
CC
TXDn