XR88C681J-F Exar Corporation, XR88C681J-F Datasheet - Page 36

• 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

Figure 12 presents the block diagram of the MC68HC11 C.
The 68HC11 can be configured to operate in a “Single
Chip” Mode or in an “Expanded Multiplexed Bus” mode. If
a device is configured to operate in the “Single Chip”
mode, the entire 64K bytes of Address space is internal to
the C IC. Please note that this does not mean that there
is 64K bytes of memory, or other addressable portions
within the device. A 68HC11 MCU configured for “Single
Chip” mode operation cannot address any components
external to the MCU.
interface the DUART to this C, then the C must operate
in the “Expanded-Multiplexed” mode. The MC68HC11 is
Rev. 2.11
MODA
Mode Control
System
Port A
Timer
MODB
Therefore, if a user desired to
Figure 12. Block Diagram of the MC68HC11 Microcontroller
XTAL EXTAL
Oscillator
Clock Logic
Bus Expansion
Strobe and Handshake Parallel I/O
Address
Port B
8
E
CPU Core
-IRQ -XIRQ -RESET
Interrupt
Address/Data
Logic
36
Control
Port C
configured into the Expanded Multiplexed mode by tying
both the MODA and MODB pin to Vcc, and then resetting
the device.
The MC68HC11 consists of 5 different multi-function
parallel ports. Each of these ports are briefly discussed.
Port A
Port A consists of 3 input pins, 4 output pins and 1
bi-directional pin. This port is used to support the Timer
System. One of the input pins can be used for the Pulse
SPI
Control
Port D
RAM 256 Bytes
SCI
A/D Converter
Port E
VRH
VRL