Microchip Technology MA330018 Data Sheet

© 2007-2012 Microchip Technology Inc.

DS70291G-page  247

The Universal Asynchronous Receiver Transmitter 
(UART) module is one of the serial I/O modules 
available in the dsPIC33FJ32MC302/304, 
dsPIC33FJ64MCX02/X04 and dsPIC33FJ128MCX02/
X04 device family. The UART is a full-duplex 
asynchronous system that can communicate with 
peripheral devices, such as personal computers, 
LIN 2.0, RS-232 and RS-485 interfaces. The module 
also supports a hardware flow control option with the 
UxCTS and UxRTS pins and also includes an IrDA

®

encoder and decoder.

The primary features of the UART module are:
• Full-Duplex, 8- or 9-bit Data Transmission through 

the UxTX and UxRX pins

• Even, Odd or No Parity options (for 8-bit data)
• One or two stop bits
• Hardware flow control option with UxCTS and 

UxRTS pins

• Fully integrated Baud Rate Generator with 16-bit 

prescaler

• Baud rates ranging from 10 Mbps to 38 bps at 

40 MIPS

• Baud rates ranging from 4 Mbps to 61 bps at 4x mode 

at 40 MIPS

• 4-deep First-In First-Out (FIFO) Transmit Data 

buffer

• 4-deep FIFO Receive Data buffer
• Parity, framing and buffer overrun error detection
• Support for 9-bit mode with Address Detect 

 

(9th bit = 1)

• Transmit and Receive interrupts
• A separate interrupt for all UART error conditions
• Loopback mode for diagnostic support
• Support for sync and break characters
• Support for automatic baud rate detection
• IrDA

®

 encoder and decoder logic

• 16x baud clock output for IrDA

®

 support

A simplified block diagram of the UART module is 
shown in 

. The UART module consists of 

these key hardware elements:
• Baud Rate Generator
• Asynchronous Transmitter
• Asynchronous Receiver

Note 1: This data sheet summarizes the features 

of the dsPIC33FJ32MC302/304, 
dsPIC33FJ64MCX02/X04 and 
dsPIC33FJ128MCX02/X04 family of 
devices. It is not intended to be a 
comprehensive reference source. To 
complement the information in this data 
sheet, refer to Section 17. “UART”
(DS70188) of the “dsPIC33F/PIC24H 
Family Reference Manual”, which is 
available from the Microchip web site 
(

www.microchip.com

).

2: Some registers and associated bits 

described in this section may not be 
available on all devices. Refer to 

 in 

this data sheet for device-specific register 
and bit information.

UxRX

Hardware Flow Control

UART Receiver

UART Transmitter

UxTX

Baud Rate Generator

UxRTS/BLCKx

IrDA

®

UxCTS

Note 1: Both UART1 and UART2 can trigger a DMA data transfer.

2: If DMA transfers are required, the UART TX/RX FIFO buffer must be set to a size of 1 byte/word 

 

(i.e., UTXISEL<1:0> = 00 and URXISEL<1:0> = 00).