Overview:

Zilog’s Digital Universal Asynchronous Receiver/Transmitter (UART) is a single-chipCMOS communications device which provides full duplex asynchronous communicationswith a 128 byte FIFO buffer, of which 64 bytes each are allocated to Receive and Transmitoperations. This device also contains a 4 kbit EEPROM and General-Purpose Input andOutput (GPIO) with programmable interrupt capability. Zilog’s Digital UART has aninternal 8 MHz oscillator, which eliminates the requirement for an external crystal oscillator.This Digital UART is controlled by the simple I²C protocol (2-Wire Interface), allowingup to eight devices in the same I²C network. Although this device is fully programmablethrough the exposed commands, it is preconfigured to operate the UART at a 57,600 baudrate; therefore, configuration is not required to access the UART or the EEPROM.Zilog’s Digital UART provides separate programmable interrupts and interrupt lines for UART notification and GPIO notifications, so the controlling device does not have to pollthe device for data.

Features：

Zilog’s Digital UART offers the following features:

• Single power supply from 1.8 V to 5.0 V

• No external crystal needed

• Minimal pin count for space saving

• Interrupt lines for UARTs and GPIOs for notification

• Control via I2C standard protocol, up to 400 K

– Up to 8 different addresses available

– Can stack up to 8 parts on same I2C network

– Ability to send multiple write commands in a single transfer

• No configuration necessary

– Default UART setting: 57600 baud, no flow control, no parity, 8 bits

– EEPROM is accessed through standard I2C EEPROM communications

– GPIO configured as inputs

• Up to two industry standard full duplex individual UART channels

– 64 byte receiver FIFO for each UART

– 64 byte transmitter FIFO for each UART

– Flow control using CTS and RTS pins

– In band flow control using XON/XOFF

– FIFO watermark settings for configuring interrupt lines

– Programmable data formats

• 5 to 8 bits data

• Odd, Even or no parity

• 1 or 2 stop bits

• Loopback for testing

– Flexible baud rate selection, in steps of 100 bits per second, up to 250K

– Programmable Interrupts

• 4 KB built-in I2C EEPROM

– Standard I2C EEPROM communications

– 300K times endurance

– 10 year retention

• General Purpose Input Output pins

– Up to 12 GPIO pins

– 2 pins can generate interrupt on change of pin value

– Each pin is fully configurable

• Individual pin configuration

• Direction (input/output)

• Open drain output option

• Weak pull up option

• Debounce option

• Quickly return to default settings

Applications：

The Digital UART is suitable for use in multiple applications; examples include:

• Point of Sale devices

• Communication bridges

• Process control

• Building/automation control

• Terminal servers

• Print systems