3.3 VOLT TIME SLOT INTERCHANGE
256 x 256
• 256 x 256 channel non-blocking switch
• Automatic signal identification (ST-BUS®, GCI)
• 8 RX inputs—32 channels at 64 Kbit/s per serial line
• 8 TX outputs—32 channels at 64 Kbit/s per serial line
• Three-state serial outputs
• Microprocessor Interface (8-bit data bus)
• Frame Integrity for data applications
• 3.3V Power Supply
• Available in 44-pin Plastic Leaded Chip Carrier (PLCC)
• Operating Temperature Range -40°C to +85°C
• 3.3V I/O with 5V Tolerant Inputs
The IDT72V8985 is a ST-BUS®/GCI compatible digital switch controlled by
and output channels. Those 256 channels are divided into 8 serial inputs and
outputs, each of which consists of 32 channels. The IDT72V8985 provides per-
channel variable or constant throughput delay modes and microprocessor read
and write access to individual channels. As an important function of a digital
switch is to maintain sequence integrity and minimize throughput delay, the
IDT72V8985 is an ideal solution for most switching needs.
Frame sequence, constant throughput delay, and guaranteed minimum
delay are high priority requirements in today’s integrated data and multimedia
networks. The IDT72V8985 provides these functions on a per-channel basis
is designed to switch 64 Kbit/s PCM or N x 64 Kbit/s data.
In Processor Mode, the microprocessor can access the input and output time
slots to control other devices such as ISDN transceivers and trunk interfaces.
internal circuit to automatically identify the polarity and format of the frame
A functional block diagram of the IDT72V8985 device is shown on page 1.
The serial streams operate continuously at 2.048 Mb/s and are arranged in
eight output (TX0-7) serial streams are provided in the IDT72V8985 device
allowing a complete 256 x 256 channel non-blocking switch matrix to be
constructed. The serial interface clock for the device is 4.096 MHz.
FUNCTIONAL BLOCK DIAGRAM
C4i F0i VCC GND
Unit Output MUX
RX3 Serial Data
RX4 Streams Memory
RX7 Microprocessor Interface
DS CS R/W A0/ DTA D0/
1. The RESET Input is only provided on the SSOP package.
IDT and the IDT logo are registered trademarks of Integrated Device Technology, Inc. The ST-BUS is a trademark of Mitel Corp.
2003 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.