Datasheet

 2009-2012 Microchip Technology Inc. DS70592D-page 173
PIC24HJXXXGPX06A/X08A/X10A
18.0 UNIVERSAL ASYNCHRONOUS
RECEIVER TRANSMITTER
(UART)
The Universal Asynchronous Receiver Transmitter
(UART) module is one of the serial I/O modules avail-
able in the PIC24HJXXXGPX06A/X08A/X10A device
family. The UART is a full-duplex asynchronous system
that can communicate with peripheral devices, such as
personal computers, LIN, RS-232 and RS-485 inter-
faces. The module also supports a hardware flow con-
trol 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
• 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
• Supports Automatic Baud Rate Detection
•IrDA
®
Encoder and Decoder Logic
• 16x Baud Clock Output for IrDA
®
Support
A simplified block diagram of the UART is shown in
Figure 18-1. The UART module consists of the key
important hardware elements:
• Baud Rate Generator
• Asynchronous Transmitter
• Asynchronous Receiver
FIGURE 18-1: UART SIMPLIFIED BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC24HJXXXGPX06A/X08A/X10A
family of devices. However, it is not
intended to be a comprehensive refer-
ence source. To complement the infor-
mation 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
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
Note 1: Both UART1 and UART2 can trigger a DMA data transfer. If U1TX, U1RX, U2TX or U2RX is selected as
a DMA IRQ source, a DMA transfer occurs when the U1TXIF, U1RXIF, U2TXIF or U2RXIF bit gets set as
a result of a UART1 or UART2 transmission or reception.
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).
UxRX
Hardware Flow Control
UART Receiver
UART Transmitter
UxTX
/BCLK
Baud Rate Generator
UxRTS
IrDA
®
UxCTS