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Preliminary Data Sheet, Rev. 5
September 1999
13
Lucent Technolgies Inc. 5-1
USS-720
Instant USB
™
USB-to-
IEEE
* 1284 Bridge
Features
Device Features:
■ Full compliance with the
Universal Serial Bus Specifi-
cation Revision 1.0
■ On-chip transceivers for USB
■ Low power consumption allows part to be powered
from USB connection
■ Dual on-chip USB packet buffers for fast response
■ Fully compatible USB host device drivers available
■ Fully compliant with USB printer device class specifi-
cation
■ Implemented in Lucent Technologies Microelectron-
ics Group’s 0.35 µm, 3 V standard-cell library
■ Complete single-chip solution in a 44-pin MQFP
■ Evaluation kit available
IEEE
1284 (Parallel) Features:
■ Transparent, fully automatic support for true bidirec-
tional communication
■ Hardware initiates and manages automatic negotia-
tion for the fastest protocol available
■ Supports standard PC parallel port register-based
operation
■ Support of multiple logical channels
■ Maximum throughput: 1.216 Mbytes/s (ECP mode)
Description
The USS-720 integrated circuit connects an
IEEE
1284
parallel port peripheral to the universal serial bus (USB).
It is designed to be a low-cost, single-chip embedded
solution requiring minimal external components. It is
suitable for a wide range of applications, from integrated
applications where the IC is mounted on a printed-
circuit board inside a product, to stand-alone applica-
tions where the chip provides a standard parallel port to
a USB-capable computer. The USS-720 software
included in the Evaluation Kit allows peripheral vendors
to evaluate and test the USS-720 device, which is
embedded in the
Centronics
†
end of a USB-to-parallel
port cable provided with the kit. This solution requires
no firmware changes on the parallel port peripheral.
* IEEE
is a registered trademark of The Institute of Electrical and
Electronics Engineers, Inc.
†
Centronics
is aregistered trademark of Centronics Data Com-
puter Corporation.
5-5109a.r6
Figure 1. Block Diagram
USS-720
IEEE
1284
PARALLEL
PORT
IEEE
1284
HOST
CONTROL
AND INTERFACE
LOGIC
NONVOLATILE
CONFIGURATION
SELECT LOGIC
USB
XCVR
UDC
CORE
USB
PORT
BUFFER
RAM
PERIPHERAL
IEEE
1284
BUFFERS
OSCILLATORPLL
EEPROM
INTERFACE
EXTERNAL SERIAL EEPROM
Note: Advisories are issued as needed to update product information. When using this data sheet for design purposes, please contact
your Lucent Technologies Microelectronics Group Account Manager to obtain the latest advisory on this product.