xr16m2550 Exar Corporation, xr16m2550 Datasheet - Page 6

• Manufacturer Part Number: xr16m2550
• Description: High Performance Low Voltage Duart With 16-byte Fifo
• Manufacturer: Exar Corporation

XR16M2550
HIGH PERFORMANCE LOW VOLTAGE DUART WITH 16-BYTE FIFO
REV. 1.0.2
1.0 PRODUCT DESCRIPTION
The XR16M2550 (M2550) provides serial asynchronous receive data synchronization, parallel-to-serial and
serial-to-parallel data conversions for both the transmitter and receiver sections. These functions are
necessary for converting the serial data stream into parallel data that is required with digital data systems.
Synchronization for the serial data stream is accomplished by adding start and stop bits to the transmit data to
form a data character (character orientated protocol). Data integrity is ensured by attaching a parity bit to the
data character. The parity bit is checked by the receiver for any transmission bit errors. The electronic circuitry
to provide all these functions is fairly complex especially when manufactured on a single integrated silicon
chip. The M2550 represents such an integration with greatly enhanced features. The M2550 is fabricated with
an advanced CMOS process.
Enhanced Features
The XR16M2550 (M2550) integrates the functions of 2 enhanced 16C550 Universal Asynchronous Receiver
and Transmitter (UART). Each UART is independently controlled its own set of device configuration registers.
The configuration registers set is 16550 UART compatible for control, status and data transfer. Additionally,
each UART channel has automatic RTS/CTS hardware flow control, automatic Xon/Xoff and special character
software flow control, infrared encoder and decoder (IrDA ver 1.0), programmable baud rate generator with a
prescaler of divide by 1 or 4, and data rate up to 16 Mbps at 3.3V with 4X sampling clock rate. The
XR16M2550 is a 1.62 V to 3.63 V device.
The rich feature set of the M2550 is available through internal registers. Selectable transmit and receive FIFO
trigger levels, programmable TX and RX baud rates, and modem interface controls are all standard features.
Following a power on reset or an external reset, the M2550 is functionally and software compatible with the
previous generation ST16C2550 and XR16L2550.
Data Rate
The M2550 is capable of operation up to 16 Mbps at 3.3V, 12.5 Mbps at 2.5V and 8 Mbps at 1.8V with 4X
sampling rate. The device can operate with an external 24 MHz crystal on pins XTAL1 and XTAL2, or external
clock source of up to 64 MHz on XTAL1 pin. With a typical crystal of 14.7456 MHz and through a software
option, the user can set the prescaler bit for data rates of up to 3.68 Mbps.
The rich feature set of the M2550 is available through the internal registers. Automatic hardware/software flow
control, selectable transmit and receive FIFO trigger levels, programmable TX and RX baud rates, infrared
encoder/decoder interface, modem interface controls, and a sleep mode are all standard features.
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