The SC16C654B/654DB is a Quad Universal Asynchronous Receiver and Transmitter (QUART) used for serial data communications. Its principal function is to convert parallel data into serial data and vice versa. The UART can handle serial data rates up to 5 Mbit/s. It comes with an Intel or Motorola interface.
The SC16C654B/654DB is pin compatible with the ST16C654 and TL16C754 and it will power-up to be functionally equivalent to the 16C454. Programming of control registers enables the added features of the SC16C654B/654DB. Some of these added features are the 64-byte receive and transmit FIFOs, automatic hardware or software flow control and infrared encoding/decoding. The selectable auto-flow control feature significantly reduces software overload and increases system efficiency while in FIFO mode by automatically controlling serial data flow using RTS output and CTS input signals. The SC16C654B/654DB also provides DMA mode data transfers through FIFO trigger levels and the TXRDY and RXRDY signals. (TXRDY and RXRDY signals are not available in the HVQFN48 package.) On-board status registers provide the user with error indications, operational status, and modem interface control. System interrupts may be tailored to meet user requirements. An internal loop-back capability allows on-board diagnostics.
The SC16C654B/654DB operates at 5 V, 3.3 V and 2.5 V, and the industrial temperature range, and is available in plastic PLCC68, LQFP64, HVQFN48 and LFBGA64 packages.
On the HVQFN48 package, only channel C has all the modem pins. Channel A and channel B have only RTS and CTS pins, and channel D does not have any modem pin.
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## Features
* 4 channel UART
* 5 V, 3.3 V and 2.5 V operation
* Industrial temperature range (-40 Cel to +85 Cel)
* SC16C654B is pin and software compatible with the industry-standard ST16C454/554, ST16C654, ST68C454/554, TL16C554
* SC16C654DB is pin and software compatible with ST16C654D, and software compatible with ST16C454/554, ST68C454/554, TL16C554
* Up to 5 Mbit/s data rate at 5 V and 3.3 V and 3 Mbit/s at 2.5 V
* 5 V tolerant inputs
* 64-byte transmit FIFO
* 64-byte receive FIFO with error flags
* Automatic software (Xon/Xoff)/hardware (RTS/CTS) flow control
* Programmable Xon/Xoff characters
* Software selectable baud rate generator
* Four selectable Receive and Transmit FIFO interrupt trigger levels
* Standard modem interface or infrared (IrDA) encoder/decoder interface
* Sleep mode
* Standard asynchronous error and framing bits (Start, Stop, and Parity Overrun Break)
* Transmit, Receive, Line Status, and Data Set interrupts independently controlled
* Fully programmable character formatting:
* 5, 6, 7, or 8-bit characters
* Even, Odd, or No Parity formats
* 1, 1 1/2 , or 2-stop bit
* Baud generation (DC to 5 Mbit/s)
* False start-bit detection
* Complete status reporting capabilities
* 3-state output TTL drive capabilities for bi-directional data bus and control bus
* Line break generation and detection
* Internal diagnostic capabilities:
* Loop-back controls for communications link fault isolation
* Prioritized interrupt system controls
* Modem control functions (CTS, RTS, DSR, DTR, RI, CD).
