DS785UM1
14-1
Copyright 2007 Cirrus Logic
1
4
1
4
14
Chapter 14
14
UART1 With HDLC and Modem Control Signals
14.1 Introduction
UART1 is the collection of a UART block along with a block to support a 9 pin modem
interface and a block to support synchronous and asynchronous HDLC protocol support for
full duplex transmit and receive. The following sections address each of these blocks.
14.2 UART Overview
Transmit and Receive data transfers through UART1 can either be managed by the DMA,
interrupt driven, or CPU polled operations. A loopback control bit is available to enable
system testing by routing the transmit data stream into the receiver.
The UART performs:
•
Serial-to-parallel conversion on data received from a peripheral device.
•
Parallel-to-serial conversion on data transmitted to the peripheral device.
The CPU reads and writes data and control/status information via the AMBA APB interface.
The transmit and receive paths are buffered with internal FIFO memories allowing up to
16 bytes to be stored independently in both transmit and receive modes.
The UART:
•
Includes a programmable baud rate generator which generates a common transmit and
receive internal clock from the UART internal reference clock input, UARTCLK.
•
Offers similar functionality to the industry-standard 16C550 UART device.
•
Supports baud rates of up to 115.2 Kbps and beyond, subject to UARTCLK reference
clock frequency.
The UART operation and baud rate values are controlled by the line control register
(UART1LinCtrl).
The UART can generate:
•
Four individually-maskable interrupts from the receive, transmit and modem status logic
blocks.
•
A single combined interrupt so that the output is asserted if any of the individual
interrupts are asserted and unmasked.
If a framing, parity or break error occurs during reception, the appropriate error bit is set, and
is stored in the FIFO. If an overrun condition occurs, the overrun register bit is set
immediately and FIFO data is prevented from being overwritten.
Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...