ST16C654 Pin Compatible With Additional

Enhancements

Supports Up To 24-MHz Crystal Input Clock

( 1.5 Mbps)

Supports Up To 48-MHz Oscillator Input

Clock ( 3 Mbps) for 5-V Operation

Supports Up To 32-MHz Oscillator Input

Clock ( 2 Mbps) for 3.3-V Operation

64-Byte Transmit FIFO

64-Byte Receive FIFO With Error Flags

Programmable and Selectable Transmit and

Receive FIFO Trigger Levels for DMA and

Interrupt Generation

Programmable Receive FIFO Trigger Levels

for Software/Hardware Flow Control

Software/Hardware Flow Control

− Programmable Xon/Xoff Characters

− Programmable Auto-RTS and Auto-CTS

Optional Data Flow Resume by Xon Any

Character

DMA Signalling Capability for Both

Received and Transmitted Data

Supports 3.3-V or 5-V Supply

Characterized for Operation From −40°C to

85°C

Software Selectable Baud Rate Generator

Prescalable Provides Additional Divide by 4

Function

Fast Access 2 Clock Cycle IOR/IOW Pulse

Width

Programmable Sleep Mode

Programmable Serial Interface

Characteristics

− 5, 6, 7, or 8-Bit Characters

− Even, Odd, or No Parity Bit Generation

and Detection

− 1, 1.5, or 2 Stop Bit Generation

False Start Bit Detection

Complete Status Reporting Capabilities in

Both Normal and Sleep Mode

Line Break Generation and Detection

Internal Test and Loopback Capabilities

Fully Prioritized Interrupt System Controls

Modem Control Functions (CTS, RTS, DSR,

DTR, RI, and CD)

description

The TL16C754B is a quad universal asynchronous receiver/transmitter (UART) with 64-byte FIFOs, automatic

hardware/software flow control, and data rates up to 3 Mbps. The TL16C754B offers enhanced features. It has

a transmission control register (TCR) that stores received FIFO threshold level to start/stop transmission during

hardware and software flow control. With the FIFO RDY register, the software gets the status of TXRDY/RXRDY

for all four ports in one access. On-chip 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

loopback capability allows onboard diagnostics.

The UART transmits data sent to it from the peripheral 8-bit bus on the TX signal and receives characters on

the RX signal. Characters can be programmed to be 5, 6, 7, or 8 bits. The UART has a 64-byte receive FIFO

and transmit FIFO and can be programmed to interrupt at different trigger levels. The UART generates its own

desired baud rate based upon a programmable divisor and its input clock. It can transmit even, odd, or no parity

and 1, 1.5, or 2 stop bits. The receiver can detect break, idle or framing errors, FIFO overflow, and parity errors.

The transmitter can detect FIFO underflow. The UART also contains a software interface for modem control

operations, and software flow control and hardware flow control capabilities.

The TL16C754B is available in 80-pin TQFP and 68-pin PLCC packages.