XR68C681

Description
The MaxLinear Dual Universal Asynchronous Receiver and Transmitter (DUART) is a data communications device that provides two fully independent full duplex asynchronous communications channels in a single package. The DUART is designed for use in microprocessor based systems and may be used in a polled or interrupt driven environment.
The XR-68C681 device offers a single IC solution for the 68000 family of microprocessors.
The DUART is fabricated using advanced two layer metal, with a high performance density EPI/CMOS 1.8 process to provide high performance and low power consumption, and is packaged in a 40 pin DIP or a 44 pin PLCC.
Features
- Two Full Duplex, Independent Channels
- Asynchronous Receiver and Transmitter
- Quadruple-Buffered Receiver, Dual Buffered Transmitter
- Programmable Stop Bits in 1/16 Bit Increments
- Internal Bit Rate Generators with 23 Different Bit Rates
- Independent Bit Rate Selection for Each Transmitter and Receiver
- External Clock Capability
- Maximum Bit Rate: 1X Clock - 1Mb/s, 16X Clock - 125Kb/s
- Normal, AUTOECHO, Local LOOPBACK and Remote LOOPBACK Modes
- Multi-function 16 Bit Counter/Timer
- Interrupt Output with Eight Maskable Interrupt Conditions
- Interrupt Vector Output on Acknowledge
- 8 General Purpose Outputs
- 6 General Purpose Inputs with Change of States Detectors on Inputs
- On-chip Oscillator for Crystal
- Standby Mode to Reduce Operating Power
- Compatible with the Motorola MC68681 and the Signetic SCC68692 Devices
- Advanced CMOS Low Power Technology
- Pb-Free, RoHS Compliant Versions Offered
Documentation
-
Datasheet
-
Application Notes
-
Manuals
-
Product Brochure
Application
- Multimedia Systems
- Serial to Parallel/Parallel to Serial Converter
- DTE for Modem Communication Systems
Design Tools
Package Type | Vcc | Temp | Mode | Version | File |
---|---|---|---|---|---|
PLCC | 5V | Commercial | Motorola | 1 | |
PLCC | 5V | Commercial | Motorola | 1 | |
PDIP | 5V | Commercial | Motorola | 1 | |
PDIP | 5V | Commercial | Motorola | 1 | |
PLCC | 5V | Industrial | Motorola | 1 | |
PLCC | 5V | Industrial | Motorola | 1 | |
PDIP | 5V | Industrial | Motorola | 1 | |
PDIP | 5V | Industrial | Motorola | 1 | |
CDIP | 5V | Industrial | Motorola | 1 | |
CDIP | 5V | Industrial | Motorola | 1 |
Packaging
Parts & Purchasing
Part Number | Pkg Code | Min Temp | Max Temp | Status | Buy Now | Order Samples |
---|---|---|---|---|---|---|
XR68C681CJ-F | PLCC44 | 0 | 70 | Active | Order | |
XR68C681CJTR-F | PLCC44 | 0 | 70 | Active | Order | |
XR68C681CP | PDIP40 | 0 | 70 | OBS |
Suggested: XR68C681CP-F |
|
XR68C681CP-F | PDIP40 | 0 | 70 | OBS |
Suggested: XR68C681CJ-F |
|
XR68C681J-F | PLCC44 | -40 | 85 | Active | Order | |
XR68C681JTR-F | PLCC44 | -40 | 85 | OBS |
Suggested: XR68C681J-F |
|
XR68C681P | PDIP40 | -40 | 85 | OBS |
Suggested: XR68C681P-F |
|
XR68C681P-F | PDIP40 | -40 | 85 | OBS |
Suggested: XR68C681J-F |
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.
Quality & Environmental Data
Part Number | RoHS | Exempt | RoHS | Halogen Free | REACH | MSL Rating / Peak Reflow | Package |
---|---|---|---|---|---|---|
XR68C681CJ-F | N | Y | Y | Y | L1 / 260ᵒC | PLCC44 |
XR68C681J-F | N | Y | Y | Y | L1 / 260ᵒC | PLCC44 |
XR68C681CJTR-F | N | Y | Y | Y | L1 / 260ᵒC | PLCC44 |
Click on the links above to download the Certificate of Non-Use of Hazardous Substances.
Support
Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
For ordering information and general customer service visit our Contact Us page.
Frequently Asked Questions
In this example, we looked for XRA1201. Click on part number header or on the link at the bottom of the result. This brings you to the product page. For example:
Click on Parts & Purchasing, highlighted with the blue arrow above. The screen changes to:
Notice the status column and the “Show obsolete parts” link. A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers, the legend still present:
Another method to find out if a part is OBS or EOL is to click on SUPPORT at the top:
And then Product Change Notifications:
Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:
If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.
Please check that all the following conditions are satisfied first.
- no interrupts pending (ISR bit-0 = 1)
- modem inputs are not toggling (MSR bits 0-3 = 0)
- RX input pin is idling HIGH • divisor (the value in DLL register) is non-zero
- TX and RX FIFOs are empty
Be sure sleep mode bit has been set to 1. If there are multiple UART channels, the sleep conditions must be true for all channels.
See more on Sleep Mode in AN204 UART Sleep Mode.
Yes. Note: some devices do have powersave mode. If UART goes into powersave mode, then the registers are not accessible.
See more on Sleep Mode in AN204 UART Sleep Mode.
Read LSR register to check whether the UART receives the data or not.
- If LSR value is 0x60, it means that either UART receiver FIFO doesn’t receive the data or the data in receiver FIFO has been read out before the read of LSR.
- If LSR value is 0x00, it means data is still in the THR (clock doesn’t oscillate to transmit data).
- If LSR value is 0xFF, it means either UART is in powersave mode or UART is powered off. For those devices with powersave mode, be sure that UARTS are not in powersave mode.
See more on Sleep Mode in AN204 UART Sleep Mode.
- Check whether the register set can be accessed.
- Check whether the crystal is oscillating fully.
- Check whether the data can be transmitted in internal loopback mode.
See more on Sleep Mode in AN204 UART Sleep Mode.
Submit a Technical Support Question As a New Question