UART IP Core H16750S Synchronous 16750 UART with FIFO & IrDA Core

On this page: Description | Implementation Results | Features | Applications | Symbol Diagram | Block Diagram | Functional Description | Support | Verification | Deliverables

The H16750S is a standard UART providing 100% software compatibility with the popular Texas Instruments 16750 device. It performs serial-to-parallel conversion on data originating from modems or other serial devices, and performs parallel-to-serial conversion on data from a CPU to these devices.

The H16750S can be run in either 16450-compatible character mode or FIFO mode, where an internal FIFO relieves the CPU of excessive software overhead. An IrDA-compliant serial data port may be used for infrared communication.

Developed for easy reuse in ASIC and FPGA applications, the H16750S is available optimized for several device families with competitive utilization and performance characteristics.

See representative implementation results (each in a new pop-up window):

Features

• Capable of running all existing 16450 and 16550a software
• Fully Synchronous design. All inputs and outputs are based on the rising edge of clock
• In FIFO mode, transmitter and receiver are each buffered with up to 256 byte FIFO’s to reduce the number of interrupts presented to the CPU
• Available with FIFO sizes of 8, 16, 32, 64, 128 or 256 bytes
• Adds or strips standard asynchronous communication bits (start, stop and parity) to or from the serial data
• Independently controlled transmit, receive, line status and data set interrupts
• Programmable baud generator divides any input clock by 1 to (2**16 - 1) and generates the 16 x clock
• Modem control functions (CTSn, RTSn, DSRn, DTRn, and DCDn)
• Programmable Auto-CTSn and Auto-RTSn
• In Auto-CTSn mode, CTSn controls the transmitter
• In Auto-RTSn mode, the receiver FIFO contents and threshold control RTSn
• Serial Port has an optional Infrared Data Association (IrDA) data port
• Fully programmable serial interface characteristics:
• 5, 6, 7, or 8 bit characters
• Even, odd, or no-parity bit generation and detection
• 1, 1½, or 2 stop bit generation
• Baud generation
• False start-bit detection
• Complete status register
• Internal diagnostic capabilities: loop-back controls for communications link fault isolation
• Full prioritized interrupt system controls

Applications

The H16750S can be utilized for a variety of applications including:

• Serial or modem computer interface
• Serial interface within modems and other devices

Symbol Diagram

Block Diagram

Functional Description

As shown in the block diagram and explained below, the H16750S includes seven major blocks: Interface, Registers, RXBlock, Interrupt Control, Baud Rate Generator, TXBlock and IrDA. All inputs and outputs for the H16750S are fully synchronous to the rising edge of the CLK input.

Interface

The Interface block is responsible for handling the communications with the processor (or parallel) side of the system. All writing and reading of internal registers is accomplished through this block.

Registers

The Registers block holds all of the device’s internal registers. See the Register Description table for details on existing registers and their addresses. Some information comes from the other blocks, however register information is gathered in the Registers block and made available to all blocks.

RXBlock

This is the receiver block. RXBlock receives the incoming serial word. It is programmable to recognize data widths such as 5, 6, 7 or 8 bits, various parity settings such as even, odd or no parity, and different stop bits such as 1, 1½ and 2 bits. RXBlock checks for errors in the input data stream such as overrun errors, frame errors, and parity errors and break errors. If the incoming word has no problems, it is placed either in the Receiver Holding register or in the Receiver FIFO depending on the mode programmed.

Interrupt Control

The Interrupt Control block sends an interrupt signal back to the processor depending on the state of the FIFO and its received and transmitted data. The Interrupt Identification register provides the level of the interrupt. Interrupts are sent in the condition of empty transmission/receiving buffers (or FIFOs), an error in receiving a character, or other conditions requiring the attention of the processor.

Baud Rate Generator

This block takes the input clock (CLK) and divides it by a programmed value (from 1 to 2**16 – 1). The result is then divided by 16 to create the transmission clock (Baudout clock).

TXBlock

The Transmit block handles the transmission of data written to the Transmission Holding register (or transmit FIFO). It adds required start, parity and stop bits to the data being transmitted so that the receiving device can do the proper error handling and receiving.

IrDA

The IrDA block is an optional addition to the H16750. It handles the same data as the SIN and SOUT only in an Infra Red Interface format.

Support

The core as delivered is warranted against defects for ninety days from purchase. Thirty days of phone and email technical support are included, starting with the first interaction. Additional maintenance and support options are available.

Verification

The core has been verified through extensive simulation and rigorous code coverage measurements.

Deliverables

The core is available in ASIC (synthesizable HDL) and FPGA (netlist) forms, and includes everything required for successful implementation:

• HDL RTL source code (ASICs) or post-synthesis EDIF netlist (FPGAs)
• Wrapper for pin compatible replacement
• Sophisticated HDL Testbench including external FIFOs, buffers, models of interfaces, and the core
• Simulation script, vectors, expected results, and comparison utility
• Synthesis script (ASICs) or place and route script (FPGAs)
• Comprehensive user documentation, including detailed specifications and a system integration guide

 

On this page: Description | Implementation Results | Features | Applications | Symbol Diagram | Block Diagram | Functional Description | Support | Verification | Deliverables

Download PDF datasheets for more info: ASIC | Altera | Xilinx