Analog Devices EV-SC594-SOM User manual

EV-SC594-SOM ® Manual
Revision 1.0, April 2021
Part Number
82-EV-SC594-SOM-01
Analog Devices, Inc.
One Technology Way
Norwood, MA 02062-9106

Copyright Information
© 2020 Analog Devices, Inc., ALL RIGHTS RESERVED. This document may not be reproduced in any form
without prior, express written consent from Analog Devices, Inc.
Disclaimer
Analog Devices, Inc. reserves the right to change this product without prior notice. Information furnished by Ana-
log Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its
use; nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under the patent rights of Analog Devices, Inc.
Trademark and Service Mark Notice
The Analog Devices logo, Blackfin, Blackfin+, SHARC, SHARC+, CrossCore, VisualDSP++, EZ-KIT, EZ-Extend-
er, and EngineerZone are registered trademarks of Analog Devices, Inc.
All other brand and product names are trademarks or service marks of their respective owners.
Regulatory Compliance
The EV-SC594-SOM evaluation board is designed to be used solely in a laboratory environment. The board is not
intended for use as a consumer-end product or as a portion of a consumer-end product. The board is an open sys-
tem design, which does not include a shielded enclosure and, therefore, may cause interference to other electrical
devices in close proximity. This board should not be used in or near any medical equipment or RF devices.
The EV-SC594-SOM evaluation board contains ESD (electrostatic discharge) sensitive devices. Electrostatic charges
readily accumulate on the human body and equipment and can discharge without detection. Permanent damage may
occur on devices subjected to high-energy discharges. Proper ESD precautions are recommended to avoid perform-
ance degradation or loss of functionality. Store unused boards in the protective shipping package.
EV-SC594-SOM ® Manual ii

Contents
Preface
Purpose of This Manual................................................................................................................................. 1–1
Manual Contents ........................................................................................................................................... 1–1
Technical Support.......................................................................................................................................... 1–2
Supported Integrated Circuit ......................................................................................................................... 1–2
Supported Tools............................................................................................................................................. 1–3
Product Information...................................................................................................................................... 1–3
Analog Devices Website.............................................................................................................................. 1–3
EngineerZone ............................................................................................................................................. 1–3
Using the Board
Product Overview .......................................................................................................................................... 2–1
Package Contents........................................................................................................................................... 2–3
Default Configuration ................................................................................................................................... 2–3
CrossCore Embedded Studio (CCES) Setup .................................................................................................. 2–4
Debug Interface ............................................................................................................................................. 2–4
Board Power .................................................................................................................................................. 2–4
Power-On-Self Test........................................................................................................................................ 2–5
Example Programs ......................................................................................................................................... 2–5
Reference Design Information ....................................................................................................................... 2–5
IS25LP512M - 512M-bit Serial Flash Memory with Dual and Quad SPI ..................................................... 2–5
IS25LX256 - 256M-bit Serial Octal Flash Memory ....................................................................................... 2–6
IS43TR16512BL - 1Gx8, 512Mx16 8Gb DDR3 SDRAM ...........................................................................2–6
LT8636 - 42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current .......... 2–7
LTC3307A - 5V, 3A Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN ................................. 2–7
LTC3310S - 5V, 10A Synchronous Step-Down Silent Switcher 2 in 3mm × 3mm LQFN ............................ 2–8
ADP151 - Ultralow Noise, 200 mA, CMOS Linear Regulator ..................................................................... 2–8
EV-SC594-SOM ® Manual iii

STUSB4500 - USB 3.0 Power Delivery......................................................................................................... 2–9
Hardware Reference
System Architecture ....................................................................................................................................... 3–1
Software-Controlled Switches (SoftConfig).................................................................................................... 3–2
Overview of SoftConfig.............................................................................................................................. 3–3
SoftConfig on the Board............................................................................................................................. 3–6
Programming SoftConfig Switches............................................................................................................. 3–6
Switches......................................................................................................................................................... 3–9
Boot Mode Select ( SW1 )........................................................................................................................... 3–9
Reset Pushbutton ( SW2 )......................................................................................................................... 3–10
Jumpers ....................................................................................................................................................... 3–10
Power ( JP1 )........................................................................................................................................... 3–10
LEDs ........................................................................................................................................................... 3–10
Fault ( LED1 ) .......................................................................................................................................... 3–11
Power ( LED3 ) ........................................................................................................................................ 3–11
GPIO ( LED2, LED4, LED5 ) ............................................................................................................ 3–11
Reset ( LED6 ).......................................................................................................................................... 3–12
Connectors .................................................................................................................................................. 3–12
JTAG ( P1 ).............................................................................................................................................. 3–13
MicroUSB Connector ( ) .......................................................................................................................... 3–13
USB Type C Connector ( P3 ).................................................................................................................. 3–14
SoM Interface Connection ( J1,J2 and J3 )...................................................................................... 3–14
iv EV-SC594-SOM ® Manual

1 Preface
Thank you for purchasing the Analog Devices, Inc. System-on-Module (SoM) EV-SC594-SOM evaluation board.
The EV-SC594-SOM primarily hosts the ADSP-SC594 audio processor, 8 Gbit of ISSI DDR3 memory, a 512 Mbit
Quad SPI FLASH, voltage regulation, a FTDI UART to USB interface, and a high speed external connector array
that contains all of the peripheral I/O signals. Through the high speed external connector array, the EV-SC594-SOM
is intended for use with a growing family of SoM carrier products that contain a variety of peripherals to support
different applications. The SoM carrier base products that exist today are the EV-SOMCRR-EZKIT and EV-
SOMCRR-AUTO .
The CrossCore Embedded Studio®(CCES) software development tool chain is required for a full evaluation of this
hardware platform. The EV-SC594-SOM can also be used in a limited standalone mode while not plugged into a
SoM Carrier such as the EV-SOMCRR-EZKIT or EV-SOMCRR-AUTO . The standalone mode is useful for evaluat-
ing the CCES Software Development Tools and benchmarking software algorithms that do not require peripheral
I/O.
The evaluation board is designed to be used in conjunction with the CrossCore Embedded Studio®2.10.0+ devel-
opment environment for advanced application code development and debug, with features that enable the ability to:
•Create, compile, assemble, and link application programs written in C++, C, and assembly
•Load, run, step, halt, and set breakpoints in application programs
•Read and write data and program memory
•Read and write core and peripheral registers
Purpose of This Manual
This manual provides instructions for installing the product hardware (board). This manual describes operation and
configuration of the board components and provides guidelines for running code on the board.
Manual Contents
The manual consists of:
•Using the board
Preface
EV-SC594-SOM ® Manual 1–1

Provides basic board information.
•Hardware Reference
Provides information about the hardware aspects of the board.
•Bill of Materials
A companion file in PDF format that lists all of the components used on the board is available on the website
at http://www.analog.com/EV-SC594-SOM .
•Schematic
A companion file in PDF format documenting all of the circuits used on the board is available on the website
at http://www.analog.com/EV-SC594-SOM .
Technical Support
You can reach Analog Devices technical support in one of the following ways:
•Post your questions in the processors and DSP support community at EngineerZone®:
http://ez.analog.com/community/dsp
•Submit your questions to technical support directly at:
http://www.analog.com/support
•E-mail your questions about processors, DSPs, and tools development software from CrossCore Embedded Stu-
dio or VisualDSP++®:
If using CrossCore Embedded Studio or VisualDSP++ choose Help > Email Support. This creates an e-mail to
processor[email protected] and automatically attaches your CrossCore Embedded Studio or Visu-
alDSP++ version information and license.dat file.
•E-mail your questions about processors and processor applications to:
processor[email protected]
processor[email protected]
•Contact your Analog Devices sales office or authorized distributor. Locate one at:
http://www.analog.com/adi-sales
Supported Integrated Circuit
This evaluation system supports the Analog Devices ADSP-SC594 IC.
Technical Support
1–2 EV-SC594-SOM ® Manual

Supported Tools
Information about code development tools for the EV-SC594-SOM evaluation board and ADSP-SC59x product
family is available at:
http://www.analog.com/EV-SC594-SOM
Product Information
Product information can be obtained from the Analog Devices website and the online help system.
Analog Devices Website
The Analog Devices website, http://www.analog.com, provides information about a broad range of products - ana-
log integrated circuits, amplifiers, converters, transceivers, and digital signal processors.
To access a complete technical library for each processor family, go to http://www.analog.com/processors/techni-
cal_library. The manuals selection opens a list of current manuals related to the product as well as a link to the
previous revisions of the manuals. When locating your manual title, note a possible errata check mark next to the
title that leads to the current correction report against the manual.
Also note, MyAnalog.com is a free feature of the Analog Devices website that allows customization of a web page to
display only the latest information about products you are interested in. You can choose to receive weekly e-mail
notifications containing updates to the web pages that meet your interests, including documentation errata against
all manuals. MyAnalog.com provides access to books, application notes, data sheets, code examples, and more.
Visit MyAnalog.com to sign up. If you are a registered user, just log on. Your user name is your e-mail address.
EngineerZone
EngineerZone is a technical support forum from Analog Devices, Inc. It allows you direct access to ADI technical
support engineers. You can search FAQs and technical information to get quick answers to your embedded process-
ing and DSP design questions.
Use EngineerZone to connect with other DSP developers who face similar design challenges. You can also use this
open forum to share knowledge and collaborate with the ADI support team and your peers. Visit http://
ez.analog.com to sign up.
Supported Tools
EV-SC594-SOM ® Manual 1–3

2 Using the Board
This chapter provides information on the major components and peripherals on the board, along with instructions
for installing and setting up the emulation software.
Product Overview
Below is an image of the EV-SC594-SOM board.
Figure 2-1: Board View
The board features:
Using the Board
EV-SC594-SOM ® Manual 2–1

•Analog Devices ADSP-SC594 processor
•Dual SHARC+ Cores
•ARM A5 Core
•400 ball BGA
•25 MHz oscillator
•DDR3 Memory
•512Mx16 bit (8Gbit )
•ISSI IS43TR16512BL-125KBL
•1.35V
•SPI Flash Quad (SPI2) Memory
•512Mbit
•ISSI IS25LP512M - 512M-bit Serial Flash Memory with Dual and Quad SPI
•Single/Dual/Quad SPI
•SPI Flash Octal (OSPI) Memory
•256Mbit
•ISSI IS25LX256 - 256M-bit Serial Octal Flash Memory
•Single/Octal SPI
•Debug Interface (JTAG)
•JTAG 10-pin 0.05” header
•LEDs
•Eight LEDs: one power (green), one board reset (red), three general-purpose (amber), one fault (red) and
two UART leds (amber)
•Pushbuttons
•One pushbutton, RESET
•SoM Interface Connector
•DAI
•SPORT
•SPI
•UART
Product Overview
2–2 EV-SC594-SOM ® Manual

•TWI
•Link Port
•GPIO
•MLB
•RESET
•GND/3.3V/5V/12V output
Package Contents
Your EV-SC594-SOM package contains the following items.
•EV-SC594-SOM board
Contact the vendor where you purchased your EV-SC594-SOM evaluation board or contact Analog Devices, Inc. if
any item is missing.
Default Configuration
The EV-SC594-SOM board is designed to run as a standalone unit.
The Default Hardware Setup figure shows the default settings for jumpers and switches and the location of the
jumpers, switches, connectors, and LEDs. Confirm that your board is in the default configuration before using the
board.
Default Config
Package Contents
EV-SC594-SOM ® Manual 2–3

Boot Mode Select
SW1
SW2
Reset Button
JP1
Power
Selection
)
Figure 2-2: Default Hardware Setup
CrossCore Embedded Studio (CCES) Setup
Information on using the CCES tools is available at: https://analog.com/cces-quickstart
Debug Interface
The EV-SC594-SOM provides a JTAG connection via P1 . This is for attaching an emulator, such as the ICE-1000
or ICE-2000 to for debugging.
When the EV-SC594-SOM is connected to a carrier board the Debug Agent on the carrier board can be used. To use
this Debug Agent, all postions on SW1 (on the carrier board) must be in the ON position. If an emulator, such as
the ICE-1000 or ICE-2000, is used instead all postions on SW1 must be in the OFF position.
Board Power
CrossCore Embedded Studio (CCES) Setup
2–4 EV-SC594-SOM ® Manual

The EV-SC594-SOM powered via when the board is in standalone mode. When in this mode the jumper on JP1
should be on Pins 1-2 to select power input from . When the EV-SC594-SOM is connected to a carrier board the
power is supplied via the carrier board. When in this mode the jumper on JP1 should be on Pins 2-3 to select
power input from the carrier board.
Power-On-Self Test
The Power-On-Self-Test Program (POST) tests all the EZ-KIT carrier board peripherals and validates functionality
as well as connectivity to the processor. Once assembled, each EZ-KIT carrier board is fully tested for an extended
period of time with POST for all the compatible SoM modules. All EZ-KIT carrier boards are shipped with POST
preloaded into flash memory. The POST is executed by resetting the board and connecting the USB To UART to
your PC with an open terminal window. The POST also can be used as a reference for a custom software design or
hardware troubleshooting.
Note that the source code for the POST program is included in the Board Support Package (BSP) along with the
readme file that describes how the board is configured to run POST.
Example Programs
Example programs are provided with the EV-SC594-SOM Board Support Package (BSP) to demonstrate various ca-
pabilities of the product. The programs can be found in the EV-SC594-SOM\examples installation folder. Re-
fer to the readme file provided with each example for more information.
Reference Design Information
A reference design info package is available for download on the Analog Devices Web site. The package provides
information on the schematic design, layout, fabrication, and assembly of the board.
The information can be found at:
http://www.analog.com/EV-SC594-SOM
IS25LP512M - 512M-bit Serial Flash Memory with Dual and
Quad SPI
The IS25LP512M Serial Flash memory offers a versatile storage solution with high flexibility and performance in a
simplified pin count package. ISSI’s “Industry Standard Serial Interface” Flash is for systems that require limited
space, a low pin count, and low power consumption. The device is accessed through a 4-wire SPI Interface consist-
ing of a Serial Data Input (SI), Serial Data Output (SO), Serial Clock (SCK), and Chip Enable (CE#) pins, which
can also be configured to serve as multi-I/O (see pin descriptions).
The device supports Dual and Quad I/O, as well as standard, Dual Output, and Quad Output SPI. Clock frequen-
cies of up to 133MHz allow for equivalent clock rates of up to 532MHz (133MHz x 4) which equates to
66.5Mbytes of data throughput. The IS25xE series of Flash adds support for DTR (Double Transfer Rate)
Power-On-Self Test
EV-SC594-SOM ® Manual 2–5

commands that transfer addresses and read data on both edges of the clock.These transfer rates can outperform 16-
bit Parallel Flash memories, allowing for efficient memory access to support XIP (eXecute In Place) operation.
The memory array is organized into programmable pages of 256/512 bytes. This family supports page program
mode where 1 to 256/512 bytes of data are programmed in a single command.
QPI (Quad Peripheral Interface) supports 2-cycle instructions, further reducing instruction times. Pages can be
erased in groups of 4Kbyte sectors, 32Kbyte blocks, 64K/256Kbyte blocks, and/or the entire chip. The uniform sec-
tor and block architecture allows for a high degree of flexibility so that the device can be utilized for a broad variety
of applications requiring solid data retention.
IS25LX256 - 256M-bit Serial Octal Flash Memory
The IS25LX256/128 and IS25WX256/128 Serial Flash memory offer a versatile storage solution with high flexibili-
ty and performance in a simplified pin count package. ISSI’s “Industry Standard Serial Interface” Flash is for systems
that require limited space, a low pin count, and low power consumption. The device is compliant with JEDEC
Standard xSPI (eXpanded Serial Peripheral Interface).
Nonvolatile and volatile configuration registers enable respective default and temporary settings such as READ oper-
ation dummy cycles and wrap modes, memory protection, output buffer impedance, SPI protocol type, and XIP
mode.
Memory is organized as uniform 128KB sectors, 4KB and 32KB subsectors, and 256 byte pages. Optional 64KB
sectors are also supported.
Direct boot in Octal DDR protocol provides high performance and ease of use, enabling communication between
host and device without need to configure extended SPI protocol operations. However, the devices still support both
extended SPI and Octal DDR protocols to ensure legacy system support and easy migration path. The extended SPI
protocol supports address and data transmission on one or eight data lines, depending on the command.
IS43TR16512BL - 1Gx8, 512Mx16 8Gb DDR3 SDRAM
•Low Voltage (L): VDD and VDDQ = 1.35V + 0.1V, -0.067V - Backward compatible to 1.5V
•High speed data transfer rates with system frequency up to 933 MHz
•8 internal banks for concurrent operation
•8n-Bit pre-fetch architecture
•Programmable CAS Latency
•Programmable Additive Latency: 0, CL-1,CL-2
•Programmable CAS WRITE latency (CWL) based on tCK
•Programmable Burst Length: 4 and 8
•Programmable Burst Sequence: Sequential or Interleave
IS25LX256 - 256M-bit Serial Octal Flash Memory
2–6 EV-SC594-SOM ® Manual

•BL switch on the fly
•Auto Self Refresh(ASR)
•Self Refresh Temperature(SRT)
•Refresh Interval: 7.8 µs (8192 cycles/64 ms) Tc= -40°C to 85°C 3.9 µs (8192 cycles/32 ms) Tc= 85°C to 95°C
1.95 µs (8192 cycles/16 ms) Tc= 95°C to 105°C 0.97 µs (8192 cycles/8 ms) Tc= 105°C to 115°C
•Partial Array Self Refresh
•Asynchronous RESET pin
•TDQS (Termination Data Strobe) supported (x8 only)
•OCD (Off-Chip Driver Impedance Adjustment)
•Dynamic ODT (On-Die Termination)
•Driver strength : RZQ/7, RZQ/6 (RZQ = 240 Ω)
•Write Leveling
•Up to 200 MHz in DLL off mode
LT8636 - 42V, 5A/7A Peak Synchronous Step-Down Silent
Switcher with 2.5µA Quiescent Current
The LT8636 synchronous step-down regulator features Silent Switcher architecture designed to minimize EMI
emissions while delivering high efficiency at high switching frequencies. Peak current mode control with a 30ns
minimum on-time allows high step-down ratios even at high switching frequencies.
The LT8636’s ultralow 2.5µA quiescent current—with the output in full regulation—enables applications requiring
highest efficiency at very small load currents. A CLKOUT pin enables synchronizing other regulators to the
LT8636.
Burst Mode operation enables ultralow standby current consumption, forced continuous mode can control frequen-
cy harmonics across the entire output load range, or spread spectrum operation can further reduce EMI emissions.
Soft-start and tracking functionality is accessed via the TR/SS pin, and an accurate input voltage UVLO threshold
can be set using the EN/UV pin.
LTC3307A - 5V, 3A Synchronous Step-Down Silent Switcher in
2mm × 2mm LQFN
The LTC3307A is a very small, high efficiency, low noise, monolithic synchronous 3A step-down DC/DC converter
operating from a 2.25V to 5.5V input supply. Using constant frequency, peak current mode control at switching
LT8636 - 42V, 5A/7A Peak Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current
EV-SC594-SOM ® Manual 2–7

frequencies up to 3MHz and minimum on-time as low as 22ns, this regulator achieves fast transient response with
small external components. Silent Switcher architecture minimizes EMI emissions.
The LTC3307A operates in forced continuous or pulse skip mode for low noise, or low-ripple Burst Mode operation
for high efficiency at light loads, ideal for battery-powered systems. The IC regulates output voltages as low as
500mV. Other features include output overvoltage protection, short-circuit protection, thermal shutdown, clock
synchronization, and up to 100% duty cycle operation for low dropout. The device is available in a low profile 12-
lead 2mm × 2mm × 0.74mm LQFN package with exposed pad for low thermal resistance.
LTC3310S - 5V, 10A Synchronous Step-Down Silent Switcher 2
in 3mm × 3mm LQFN
The LTC3310S is a very small, low noise, monolithic step-down DC/DC converter capable of providing up to 10A
of output current from a 2.25V to 5.5V input supply. The device employs Silent Switcher 2 architecture with inter-
nal hot loop bypass capacitors to achieve both low EMI and high efficiency at switching frequencies as high as
5MHz. For systems with higher power requirements, multi-phasing parallel converters is readily implemented.
The LTC3310S uses a constant-frequency, peak current mode control architecture for fast transient response. A
500mV reference allows for low voltage outputs. 100% duty cycle operation delivers low drop out.
Other features include a power good signal when the output is in regulation, precision enable threshold, output
overvoltage protection, thermal shutdown, a temperature monitor, clock synchronization, mode selection and out-
put short circuit protection.
ADP151 - Ultralow Noise, 200 mA, CMOS Linear Regulator
The ADP151 is an ultralow noise, low dropout (LDO) linear regulator that operates from 2.2 V to 5.5 V and pro-
vides up to 200 mA of output current. The low 135 mV dropout voltage at 200 mA load improves efficiency and
allows operation over a wide input voltage range.
Using an innovative circuit topology, the ADP151 achieves ultralow noise performance without the necessity of a
bypass capacitor, making the device ideal for noise-sensitive analog and RF applications. The ADP151 also achieves
ultralow noise performance without compromising the power supply rejection ratio (PSRR) or transient line and
load performance. The low 265 µA of operating supply current at 200 mA load makes the ADP151 suitable for
battery-operated portable equipment.
The ADP151 also includes an internal pull-down resistor on the EN input.
The ADP151 is specifically designed for stable operation with tiny 1 µF, ±30% ceramic input and output capacitors
to meet the requirements of high performance, space constrained applications.
The ADP151 is capable of 16 fixed output voltage options, ranging from 1.1 V to 3.3 V.
LTC3310S - 5V, 10A Synchronous Step-Down Silent Switcher 2 in 3mm × 3mm LQFN
2–8 EV-SC594-SOM ® Manual

Short-circuit and thermal overload protection circuits prevent damage in adverse conditions. The ADP151 is availa-
ble in tiny 5-lead TSOT, 6-lead LFCSP, and 4-ball, 0.4 mm pitch, halide-free WLCSP packages for the smallest
footprint solution to meet a variety of portable power application requirements.
STUSB4500 - USB 3.0 Power Delivery
The STUSB4500 is a USB power delivery controller that addresses sink devices. It implements a proprietary algo-
rithm to allow the negotiation of a power delivery contract with a source without MCU support (auto-run mode).
PDO profiles are configured in an integrated non-volatile memory.
The device supports dead battery mode and is suited for sink devices powered from dead battery state and requiring
high power charging profile to be fully operational. Thanks to its 20 V technology, it implements high voltage fea-
tures to protect the CC pins against short-circuits to VBUS up to 22 V and to support high voltage on the VBUS
pins directly connected to the VBUS power path up to 28 V.
STUSB4500 - USB 3.0 Power Delivery
EV-SC594-SOM ® Manual 2–9

3 Hardware Reference
This chapter describes the hardware design of the EV-SC594-SOM .
System Architecture
The board's configuration is shown in the Block Diagram figure.
Hardware Reference
EV-SC594-SOM ® Manual 3–1

ADSP-SC594
DDR3SPI2
TWI HADC
512Mb
Flash 8GB DDR3
UART2
FTDI RS232
DAI0/1
SPI
UART
LEDs GPIO
Power
LT8636A/LTC3307A/
LTC3310A/ADP151
LinkPort MLB/
CAN
Si5356A
Clock
USB Type C
Power
Delviery
Jumper
High Speed Connectors
ETH
JTAG
Debug
Header
OSPI
256Mb
Flash
Figure 3-1: Block Diagram
This System on Module is designed to demonstrate the ADSP-SC594 processor’s capabilities. The board has a 25
MHz input clock and runs at a max core clock frequency of 1GHz.
User I/O to the processor is provided in the form of two pushbuttons and three LEDs.
The software-controlled switches (SoftConfig) facilitate the switch multi-functionality by disconnecting the push-
buttons from their associated processor pins and reusing the pins elsewhere on the board.
Software-Controlled Switches (SoftConfig)
On the board, most of the traditional mechanical switches and jumpers have been replaced by I2C software-control-
led switches. The remaining mechanical switches are provided for the boot mode and pushbuttons. Reference any
SoftConfig*.c file found in the installation directory for an example of how to set up the SoftConfig feature of
Software-Controlled Switches (SoftConfig)
3–2 EV-SC594-SOM ® Manual

the board through software. The SoftConfig section of this manual serves as a reference to any user that intends to
modify an existing software example. If software provided by ADI is used, there should be little need to reference
this section.
NOTE: Care should be taken when changing SoftConfig settings not to create a conflict with interfaces. This is
especially true when connecting extender cards.
Overview of SoftConfig
In order to further clarify the use of electronic single FET switches and multi-channel bus switches, an example of
each is illustrated and compared to a traditional mechanical switching solution. This is a generic example that uses
similar FET and bus switch components that are on the board.
After this generic discussion there is a detailed explanation of the SoftConfig interface specific to the EV-SC594-
SOM .
The Example of Individual FET Switches figure shows two individual FET switches (Pericom PI3A125CEX) with
reference designators UA and UB. Net names ENABLE_A and ENABLE_B control UA and UB. The default FET
switch enable settings in this example are controlled by resistors RA and RB which pull the enable pin 1 of UA and
UB to ground (low). In a real example, these enable signals are controlled by the Microchip IO expander. The de-
fault pull-down resistors connects the signals EXAMPLE_SIGNAL_A and EXAMPLE_SIGNAL_B and also con-
nects signals EXAMPLE_SIGNAL_C and EXAMPLE_SIGNAL_D. To disconnect EXAMPLE_SIGNAL_A from
EXAMPLE_SIGNAL_B, the Microchip IO expander is used to change ENABLE_A to a logic 1 through software
that interfaces with the Microchip. The same procedure for ENABLE_B disconnects EXAMPLE_SIGNAL_C from
EXAMPLE_SIGNAL_D.
Figure 3-2: Example of Individual FET Switches
Software-Controlled Switches (SoftConfig)
EV-SC594-SOM ® Manual 3–3

The following figure shows the equivalent circuit to the Example of Individual FET Switches figure but utilizes me-
chanical switches that are in the same package. Notice the default is shown by black boxes located closer to the ON
label of the switches. In order to disconnect these switches, physically move the switch to the OFF position.
Figure 3-3: Example of a Mechanical Switch (Equivalent to Example of Individual FET Switches Figure)
The Example of Bus Switch figure shows a bus switch example, reference designator UC (Pericom
PI3LVD512ZHE), selecting between lettered functionality and numbered functionality. The signals on the left side
are multiplexed signals with naming convention letter_number. The right side of the circuit shows the signals sepa-
rated into letter and number, with the number on the lower group (0B1) and the letter on the upper group (0B2).
The default setting is controlled by the signal CONTROL_LETTER_NUMBER which is pulled low. This selects the
number signals on the right to be connected to the multiplexed signals on the left by default. In this example, the
Microchip IO expander is not shown but controls the signal CONTROL_LETTER_NUMBER and allows the user to
change the selection through software.
Software-Controlled Switches (SoftConfig)
3–4 EV-SC594-SOM ® Manual