Z51F0410 Datasheet, PDF (99/184 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F0410
Product Specification
4.6 USART
4.6.1 Overview
The Universal Synchronous and Asynchronous serial Receiver and Transmitter (USART) is a highly
flexible serial communication device. The main features are listed below.
- Full Duplex Operation (Independent Serial Receive and Transmit Registers)
- Asynchronous or Synchronous Operation
- Master or Slave Clocked Synchronous and SPI Operation
- Supports all four SPI Modes of Operation (Mode 0, 1, 2, 3)
- LSB First or MSB First Data Transfer @SPI mode
- High Resolution Baud Rate Generator
- Supports Serial Frames with 5,6,7,8, or 9 Data Bits and 1 or 2 Stop Bits
- Odd or Even Parity Generation and Parity Check Supported by Hardware
- Data OverRun Detection
- Framing Error Detection
- Digital Low Pass Filter
- Three Separate Interrupts on TX Complete, TX Data Register Empty and RX Complete
- Double Speed Asynchronous Communication Mode
USART has three main parts of Clock Generator, Transmitter and Receiver. The Clock Generation
logic consists of synchronization logic for external clock input used by synchronous or SPI slave
operation, and the baud rate generator for asynchronous or master (synchronous or SPI) operation.
The Transmitter consists of a single write buffer, a serial shift register, parity generator and control
logic for handling different serial frame formats. The write buffer allows a continuous transfer of data
without any delay between frames. The receiver is the most complex part of the USART module due
to its clock and data recovery units. The recovery unit is used for asynchronous data reception. In
addition to the recovery unit, the Receiver includes a parity checker, a shift register, a two level
receive FIFO (UDATAn) and control logic. The Receiver supports the same frame formats as the
Transmitter and can detect Frame Error, Data OverRun and Parity Errors.
PS029502-0212
PRELIMINARY
96