XR16M554 Datasheet, PDF (1/46 Pages) Exar Corporation – 1.62V TO 3.63V QUAD UART WITH 16-BYTE FIFO

XR16M554/554D
1.62V TO 3.63V QUAD UART WITH 16-BYTE FIFO
MAY 2008
REV. 1.0.0
GENERAL DESCRIPTION
The XR16M554 (M554) is a quad Universal
Asynchronous Receiver and Transmitter (UART) with
16 bytes of transmit and receive FIFOs, selectable
receive FIFO trigger levels and data rates of up to 4
Mbps at 3.3 V. Each UART has a set of registers that
provide the user with operating status and control,
receiver error indications, and modem serial interface
controls. An internal loopback capability allows
onboard diagnostics. The M554 is available in a 48-
pin QFN, 64-pin LQFP, 68-pin PLCC and 80-pin
LQFP packages. The 64-pin and 80-pin packages
only offer the 16 mode interface, but the 48- and 68-
pin packages offer an additional 68 mode interface
which allows easy integration with Motorola
processors. The XR16M554IV (64-pin) offers three
state interrupt output while the XR16M554DIV
provides continuous interrupt output. The XR16M554
is compatible with the industry standard ST16C554.
FEATURES
• Pin-to-pin compatible with ST16C454, ST16C554,
TI’s TL16C554A and NXP’s SC16C554B
• Intel or Motorola Data Bus Interface select
• Four independent UART channels
■ Register Set Compatible to 16C550
■ Data rates of up to 4 Mbps at 3.3 V, 3.125
Mbps at 2.5 V and 2 Mbps at 1.8 V
■ 16 byte Transmit FIFO
■ 16 byte Receive FIFO with error tags
■ 4 Selectable RX FIFO Trigger Levels
■ Full modem interface
• 1.62V to 3.63V supply operation
• Crystal oscillator or external clock input
APPLICATIONS
• Portable Appliances
• Telecommunication Network Routers
• Ethernet Network Routers
• Cellular Data Devices
• Factory Automation and Process Controls
FIGURE 1. XR16M554 BLOCK DIAGRAM
A2:A0
D7:D0
IOR#
IOW#
CSA#
CSB#
CSC#
CSD#
INTA
INTB
INTC
INTD
TXRDY# A-D
RXRDY# A-D
Reset
16/68#
INTSEL
Data Bus
Interface
UART Channel A
UART ^{16 Byte TX FIFO}
Regs
TX & RX
BRG
16 Byte RX FIFO
UART Channel B
(same as Channel A)
UART Channel C
(same as Channel A)
UART Channel D
(same as Channel A)
Crystal Osc / Buffer
1.62 V to 3.6 V VCC
GND
TXA, RXA, DTRA#,
DSRA#, RTSA#, CTSA#,
CDA#, RIA#
TXB, RXB, DTRB#,
DSRB#, RTSB#, CTSB#,
CDB#, RIB#
TXC, RXC, DTRC#,
DSRC#, RTSC#, CTSC#,
CDC#, RIC#
TXD, RXD, DTRD#,
DSRD#, RTSD#, CTSD#,
CDD#, RID#
XTAL1
XTAL2
554 BLK
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com