.
SSC050
I
2
C Backplane Controller
Product Brief
Overview
The SSC050 I
2
C
Backplane Controller is a CMOS
integrated circuit, which enables a system designer
to reduce system cost by integrating all of the digital
logic typically required in a storage enclosure. The
SSC050 may be used in any embedded control
application including parallel SCSI, Fibre Channel
or any other application where the monitoring and
control of a large number of digital I/O signals is
required. Programming the SSC050 is easy
through a convenient programming model, which
reduces the overall duration of the design-in cycle.
Data is read and written to the device over an
addressable (3-bit) I
2
C serial interface, allowing
multiple SSC050 devices on a single two-wire bus.
Device Features
I
2
C
Serial Interface (DC to 400Khz)
4 Fan Speed Monitor Inputs
40 Programmable, Bi-directional I/O Pins
Flexible FC-AL Port Bypass Control Logic
Bit Programmable Interrupt Control
Seven LED Flash Rates
64 PQFP Package
I
2
C Serial Interface
The SSC050 uses an I
2
C serial interface to
communicate with embedded controllers such as
Vitesse's SSC100/200 and VSC205/210. The slave
interface on the SSC050 uses a three-bit (A2:0)
addressing scheme for identification on the serial
interface. The ASEL pin determines the four-bit
device type identifier. Up to sixteen, SSC050 or
VCS055 devices may reside on a single I
2
C serial
interface.
I/O Pins
The SSC050 has forty bi-directional I/O pins. The
functionality of these pins is configurable via
programming of the SSC050. All I/O pins have a
12mA drive strength and support 3.3V TTL. To
enable the designer to configure and program the
SSC050, the forty I/Os are arranged in registers of
eight pins. Certain groups of pins have additional
functionality beyond simple input or output to
support the integrated fan speed sensors and
FC-AL port bypass control.
Drive Bay 1
Drive Bay 2
Drive Bay 3
Drive Bay 4
VSC7122
VITESSE
Backplane
Controller
(VSC050)
Local I/O (x8)
VITESSE
Embedded
Controller
(SSC100)
Temperature
Sensor (LM75)
Flash
(64K x 8)
I
2
C Serial
Interface
PBC_EN1
PBC_EN2
PBC_EN3
PBC_EN4
Power Supplies
LEDs (x8)
PBC_EN
Fans (x4)
VSC7120
Cu or
Optics
X24C16
EEPROM
VSC7120
PBC_EN
Application for a Single Loop, Single Controller with Four Drives
.
LED Flash Rate Control
The built-in flexibility of the SSC050 allows all forty
of the I/O pins to drive LEDs through a pull-up
resistor. Each pin is independently programmed to
flash an LED at one of seven predefined flash rates.
Fan Speed Sensors
The SSC050 includes four pins (P2.4 to P2.7),
which may be configured as fan speed sensors.
This feature enables the designer to provide high
value monitoring features at significantly reduced
costs. Embedded controllers may access the
SSC050 to determine the rotational speed (RPM) of
fans attached to each of the four inputs. The
SSC050 may also be programmed to signal an
interrupt if any one of the speed sensors fall below
the designer's predefined level.
FC-AL Port Bypass Control
Up to sixteen of the forty I/Os may be configured to
monitor and manage FC-AL port bypass control
devices. Eight pairs of I/Os include special logic to
monitor Enable Bypass signals, which may be
generated by FC-AL disk drives, and control Port
Bypass Control Enable (PBC_Enx) signals on port
bypass devices such as Vitesse's VSC7122.
The unique functionality of the SSC050 provides
the system designer with additional flexibility and
control over the port bypass function in a FC-AL
enclosure. This allows system designers to
differentiate and add value by controlling when and
how a drive is removed or inserted into a FC-AL
enclosure.
This feature may also be used for non-FC-AL
applications. It is useful wherever system
designers require flexible monitoring and control of
backplane signals.
Interrupt Support
There are up to forty interrupt sources within the
SSC050. I/O pin signal transitions, fan speed
sensor threshold levels and transitions on port
bypass inputs may be configured to generate
interrupts. Advanced interrupt priority and
management logic provides the system designer
with maximum flexibility and a simple and
convenient programming method for handling
interrupts.
Related Documents
VSC050 Data Manual
SSC100/200/VSC205/210 Data Manual
Any SDK Specification
For More Information:
www.vitesse.com
email: prodinfo@vitesse.com
TEL: 1-800-VITESSE
FAX: 805/987-5896
Vitesse Semiconductor Corporation reserves the right to make
changes in its products, specifications or other information at any
time without prior notice. Therefore the reader is cautioned to
confirm that this datasheet is current prior to placing any orders.
The company assumes no responsibility for any circuitry
described other than circuitry entirely embodied in a Vitesse
product. (Version 1.0)
2000 Vitesse Semiconductor Corporation, All Rights
Reserved.
P0.0 - P0.7
P1.0 - P1.7
P2.0 - P2.7
P3.0 - P3.7
I/O Control
and LED
Flash
Fan Speed
Sensors
Port Bypass
Control
P4.0 - P4.7
Interrupt
Priority and
Control
Two-Wire
Slave I/F
Power
On Reset
Clock
INT#
A2-A0
ASEL
SCL
SDA
OSCI
OSCO
I/O Ports
SSC050 Block Diagram
PDF 
ZIP