XESS XStend User manual

XStend Board Manual
XESS Corporation
Copyright ©1998 by X Engineering Software Systems Corporation.
All XS-prefix product designations are trademarks of X Engineering Software Systems.
All XC-prefix product designations are trademarks of Xilinx
ABEL is a trademark of DATA I/O Corporation.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in
any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior
written permission of the publisher. Printed in the United States of America.
Limited Warranty
X Engineering Software Systems Corp. (XESS) warrants that the Product, in the course of its normal use, will be
free from defects in material and workmanship for a period of one (1) year and will conform to XESS’s
specification therefor. This limited warranty shall commence on the date appearing on your purchase receipt.
XESS shall have no liability for any Product returned if XESS determines that the asserted defect a) is not present,
b) cannot reasonably be rectified because of damage occurring before XESS receives the Product, or c) is
attributable to misuse, improper installation, alteration, accident or mishandling while in your possession. Subject
to the limitations specified above, your sole and exclusive warranty shall be, during the period of warranty
specified above and at XESS’s option, the repair or replacement of the product. The foregoing warranty of XESS
shall extend to repaired or replaced Products for the balance of the applicable period of the original warranty or
thirty (30) days from the date of shipment of a repaired or replaced Product, whichever is longer.
THE FOREGOING LIMITED WARRANTY IS XESS’S SOLE WARRANTY AND IS APPLICABLE ONLY TO
PRODUCTS SOLD AS NEW. THE REMEDIES PROVIDED HEREIN ARE IN LIEU OF a) ANY AND ALL
OTHER REMEDIES AND WARRANTIES, WHETHER EXPRESSED OR IMPLIED OR STATUTORY,
INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE, AND b) ANY AND ALL OBLIGATIONS AND LIABILITIES OF XESS
FOR DAMAGES INCLUDING, BUT NOT LIMITED TO ACCIDENTAL, CONSEQUENTIAL, OR SPECIAL
DAMAGES, OR ANY FINANCIAL LOSS, LOST PROFITS OR EXPENSES, OR LOST DATA ARISING OUT
OF OR IN CONNECTION WITH THE PURCHASE, USE OR PERFORMANCE OF THE PRODUCT, EVEN IF
XESS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
In the United States, some statutes do not allow exclusion or limitations of incidental or consequential damages,
so the limitations above may not apply to you. This warranty gives you specific legal rights, and you may also
have other rights which vary from state to state.
Table of Contents
1 XStend Overview ......................................................... 3
2 XStend Board Features ................................................... 3
2.1 XS40/XS95 Board Mounting Area ........................................ 4
2.2 LEDs ................................................................. 4
2.3 Switches ............................................................. 6
2.4 VGA Interface ........................................................ 7

2.5 PS/2 Keyboard Interface .............................................. 8
2.6 RAMs ................................................................. 8
2.7 Stereo Codec ........................................................ 10
2.8 Prototyping Area .................................................... 11
2.9 Daughterboard Connector ............................................. 12
3 Example Designs for the XStend Board ................................... 12
3.1 Using the LEDs and Switches ......................................... 12
3.2 Using the VGA Interface ............................................. 16
3.3 Using the PS/2 Keyboard Interface ................................... 21
3.4 Using the RAMs ...................................................... 24
3.5 Using the Stereo Codec .............................................. 24
4 Connections between XStend/XS Board resources .......................... 24

Getting Help!
If you follow the instructions in this manual and you encounter problems, here are some places to
get help:
•If you can't get the XS Board hardware to work, send an e-mail message describing your
problem to [email protected] or check our web site at
http://www.xess.com/FPGA.
•If you can't get your XILINX software tools installed properly, send an e-mail message
describing your problem to [email protected] or check their web site at
http://www.xilinx.com/support/searchtd.htm.
1XStend Overview
The XS40 and XS95 Boards offer a flexible, low-cost method of prototyping FPGA and CPLD
designs. However, their small physical size limits the amount of support circuitry they can hold.
The XStend Board removes this limitation by providing additional support circuitry that the
XS40 and XS95 Boards can access through their breadboard interfaces.
The XStend Board contains resources that extend the range of applications of the XS Boards
into three areas:
•The pushbuttons, DIP switches, LEDs, and prototyping area are useful for basic lab
experiments. These features in combination with the XS Boards replicates the functionality
of the older HW/UW FPGABOARD.
•The VGA monitor interface, PS/2 keyboard/mouse interface, and static RAM let the XS
Boards be used in video and computing experiments.
•The stereo codec and dual-channel analog input/output circuitry are useful for processing of
audio signals in combination with DSP circuits synthesized with XILINX's CORE generation
software.
2XStend Board Features
The XStend Board extends the capabilities of the XS40 and XS95 Boards by providing
•mounting receptacles for both an XS40 and an XS95 Board;
•a 3"×3" prototyping area;
•a 42×2 connector for add-on daughterboards.
•additional LEDs and LED displays;

•pushbutton and DIP switches;
•an interface to VGA monitors;
•an interface to a PS/2-style keyboard or mouse;
•an additional 64 Kbytes of static RAM;
•a stereo codec with left/right input and output channels;
Each of these resources will be described below.
2.1 XS40/XS95 Board Mounting Area
An XS40 or XS95 Board is mounted on the XStend Board using mounting receptacle J1 or J2,
respectively. These receptacles mate with the breadboard interface of the XS Boards to give
them access to all the resources of the XStend Board. The XS Boards also provide power to the
XStend Board through these receptacles.
*Warning: Version 1.0 of the XS40 Board with a 3.3V XC4000XL FPGA will not work with the
XStend Board! You must replace the XC4000XL FPGA with an XC4000E FPGA and
remove the J8 jumper to switch the board to 5V operation.
To use an XS40 Board with the XStend Board, insert it into the right-most columns of the
mounting receptacles. When using an XS95 Board, however, you should insert it into the left-
most columns. There are markings on the XStend Board to indicate which column is ocuppied
by each type of XS Board.
2.2 LEDs
The XStend Board provides an additional eight LEDs (D1—D8) and two more LED displays
(U1 and U2) for use by the XS Boards. All of these LEDs are active-low meaning that an LED
or LED display segment will glow when a logic-low is applied to it.
The LEDs are disabled by removing the shunts on the following jumpers:
Table 1:Jumper settings for XStend LEDs.
Jumper Setting
J8 Removing the shunt on this jumper disconnects the
power from LEDs D1—D8.
J4 Removing the shunt on this jumper disconnects the
power to the left LED display U1.

J7 Removing the shunt on this jumper disconnects the
power to the right LED display U2.
Here are the connections from the XS40 and XS95 Boards to the LEDs on the XStend Board
(expressed as UCF constraints):
Listing 1:Connections between the XStend LEDs and the XS40.
# LEFT LED DIGIT SEGMENT CONNECTIONS (ACTIVE-LOW)
NET LS_0 LOC=P3;
NET LS_1 LOC=P4;
NET LS_2 LOC=P5;
NET LS_3 LOC=P78;
NET LS_4 LOC=P79;
NET LS_5 LOC=P82;
NET LS_6 LOC=P83;
NET LDP_ LOC=P84;
#
# RIGHT LED DIGIT SEGMENT CONNECTIONS (ACTIVE-LOW)
NET RS_0 LOC=P59;
NET RS_1 LOC=P57;
NET RS_2 LOC=P51;
NET RS_3 LOC=P56;
NET RS_4 LOC=P50;
NET RS_5 LOC=P58;
NET RS_6 LOC=P60;
NET RDP_ LOC=P28;
#
# INDIVIDUAL LED CONNECTIONS (ACTIVE-LOW)
NET D_1 LOC=P41;
NET D_2 LOC=P40;
NET D_3 LOC=P39;
NET D_4 LOC=P38;
NET D_5 LOC=P35;
NET D_6 LOC=P81;
NET D_7 LOC=P80;
NET D_8 LOC=P10;

Listing 2:Connections between the XStend LEDs and the XS95.
# LEFT LED DIGIT SEGMENT CONNECTIONS (ACTIVE-LOW)
NET LS_0 LOC=P1;
NET LS_1 LOC=P2;
NET LS_2 LOC=P3;
NET LS_3 LOC=P75;
NET LS_4 LOC=P79;
NET LS_5 LOC=P82;
NET LS_6 LOC=P83;
NET LDP_ LOC=P84;
#
# RIGHT LED DIGIT SEGMENT CONNECTIONS (ACTIVE-LOW)
NET RS_0 LOC=P58;
NET RS_1 LOC=P56;
NET RS_2 LOC=P54;
NET RS_3 LOC=P55;
NET RS_4 LOC=P53;
NET RS_5 LOC=P57;
NET RS_6 LOC=P61;
NET RDP_ LOC=P34;
#
# INDIVIDUAL LED CONNECTIONS (ACTIVE-LOW)
NET D_1 LOC=P44;
NET D_2 LOC=P43;
NET D_3 LOC=P41;
NET D_4 LOC=P40;
NET D_5 LOC=P39;
NET D_6 LOC=P37;
NET D_7 LOC=P36;
NET D_8 LOC=P35;
2.3 Switches
The XStend has a bank of eight DIP switches and two pushbuttons (labelled SPARE and
RESET) that are accessible from the XS Boards. (There is a third pushbutton labelled
PROGRAM which is used to initiate the programming of the XS40 Board. It is not intended to
be a general-purpose input.)
When closed, each DIP switch pulls the connected pin of the XS Board to ground. When the
DIP switch is open, the pin is pulled high through a 10KWresistor.
*When not being used, the DIP switches should be left in the open configuration so the pins of
the XS Board are not tied to ground and can freely move between logic low and high levels.
When pressed, each pushbutton pulls the connected pin of the XS Board to ground. Otherwise,
the pin is pulled high through a 10 KWresistor.
Here are the connections from the XS40 and XS95 Boards to the switches on the XStend Board
expressed as UCF constraints (for the UCF syntax and usage tips, check out
http://www.xilinx.com/techdocs/2449.htm):

Listing 3: Connections between the XStend DIP and pushbutton switches and the XS40.
# DIP SWITCH CONNECTIONS
NET DIPSW1 LOC=P7;
NET DIPSW2 LOC=P8;
NET DIPSW3 LOC=P9;
NET DIPSW4 LOC=P6;
NET DIPSW5 LOC=P77;
NET DIPSW6 LOC=P70;
NET DIPSW7 LOC=P66;
NET DIPSW8 LOC=P69;
#
# PUSHBUTTON SWITCH CONNECTIONS (ACTIVE-LOW)
NET PUSH_SPARE_ LOC=P67;
NET PUSH_RESET_ LOC=P37;
Listing 4:Connections between the XStend DIP and pushbutton switches and the XS95.
# DIP SWITCH CONNECTIONS
NET DIPSW1 LOC=P6;
NET DIPSW2 LOC=P7;
NET DIPSW3 LOC=P11;
NET DIPSW4 LOC=P5;
NET DIPSW5 LOC=P72;
NET DIPSW6 LOC=P71;
NET DIPSW7 LOC=P66;
NET DIPSW8 LOC=P70;
#
# PUSHBUTTON SWITCH CONNECTIONS (ACTIVE-LOW)
NET PUSH_SPARE_ LOC=P67;
NET PUSH_RESET_ LOC=P10;
2.4 VGA Interface
The XStend Board provides the XS Board with an interface to a VGA monitor through
connector J5. The XS Board can drive the active-low horizontal and vertical sync signals and
control the width and height of the video frame. The XS Board also has access to two bits each
of red, green, and blue color signals so it can generate pixels in any of 22×22×22=64 different
colors.
Here are the connections from the XS40 and XS95 Boards to the VGA interface of the XStend
Board (expressed as UCF constraints):
Listing 5:Connections between the XStend VGA interface and the XS40.
# VGA CONNECTIONS
NET VSYNC_ LOC=P67;
NET HSYNC_ LOC=P19;
NET RED1 LOC=P18;
NET RED0 LOC=P23;
NET GREEN1 LOC=P20;
NET GREEN0 LOC=P24;
NET BLUE1 LOC=P26;
NET BLUE0 LOC=P25;

Listing 6:Connections between the XStend VGA interface and the XS95.
# VGA CONNECTIONS
NET VSYNC_ LOC=P24;
NET HSYNC_ LOC=P15;
NET RED1 LOC=P14;
NET RED0 LOC=P18;
NET GREEN1 LOC=P17;
NET GREEN0 LOC=P19;
NET BLUE1 LOC=P23;
NET BLUE0 LOC=P21;
2.5 PS/2 Keyboard Interface
The XStend Board provides the XS Board with a PS/2-style interface (mini-DIN connector J6)
to either a keyboard or a mouse. The XS Board receives two signals from the PS/2 interface: a
clock signal and a serial data stream that is synchronized with the falling edges on the clock
signal.
Here are the connections from the XS40 and XS95 Boards to the PS/2 interface of the XStend
Board (expressed as UCF constraints):
Listing 7: Connections between the XStend PS/2 interface and the XS40.
# PS/2 KEYBOARD CONNECTIONS
NET KB_DATA LOC=P69;
NET KB_CLK LOC=P68;
Listing 8:Connections between the XStend PS/2 interface and the XS95.
# PS/2 KEYBOARD CONNECTIONS
NET KB_DATA LOC=P70;
NET KB_CLK LOC=P26;
2.6 RAMs
The XStend Board adds an additional 64 KBytes of RAM to the 32 KBytes already on the XS
Board. The XStend RAM connects to the same pins as the XS Board RAM for the address bus,
data bus, write-enable, and output-enable. The chip-selects of the XStend Board RAMs are
connected to different pins so all the RAMs can be individually selected.
The XStend RAMs are disabled by removing the shunts on the following jumpers:

Table 2:Jumper settings for XStend RAMs.
Jumper Setting
J16 Removing the shunt on this jumper disables the left
RAM U5 by pulling its chip-select pin high.
J17 Removing the shunt on this jumper disables the right
RAM U6 by pulling its chip-select pin high.
Here are the connections from the XS40 and XS95 Boards to their own RAMs and the RAMs of
the XStend Board (expressed as UCF constraints):
Listing 9:Connections between the XStend RAMs and the XS40.
NET AD0 LOC=P41; # DATA BUS
NET AD1 LOC=P40;
NET AD2 LOC=P39;
NET AD3 LOC=P38;
NET AD4 LOC=P35;
NET AD5 LOC=P81;
NET AD6 LOC=P80;
NET AD7 LOC=P10;
NET A0 LOC=P3; # LOWER BYTE OF ADDRESS
NET A1 LOC=P4;
NET A2 LOC=P5;
NET A3 LOC=P78;
NET A4 LOC=P79;
NET A5 LOC=P82;
NET A6 LOC=P83;
NET A7 LOC=P84;
NET A8 LOC=P59; # UPPER BYTE OF ADDRESS
NET A9 LOC=P57;
NET A10 LOC=P51;
NET A11 LOC=P56;
NET A12 LOC=P50;
NET A13 LOC=P58;
NET A14 LOC=P60;
NET A15 LOC=P28;
NET WR_ LOC=P62; # ACTIVE-LOW WRITE-ENABLE FOR ALL RAMS
NET OE_ LOC=P61; # ACTIVE-LOW OUTPUT-ENABLE FOR ALL RAMS
NET CE_ LOC=P65; # ACTIVE-LOW CHIP-ENABLE FOR XS40 RAM
NET LCE_ LOC=P7; # ACTIVE-LOW CHIP-ENABLE FOR LEFT XSTEND RAM
NET RCE_ LOC=P8; # ACTIVE-LOW CHIP-ENABLE FOR RIGHT XSTEND RAM
Listing 10:Connections between the XStend RAMs and the XS95.
NET AD0 LOC=P44; # DATA BUS
NET AD1 LOC=P43;
NET AD2 LOC=P41;
NET AD3 LOC=P40;
NET AD4 LOC=P39;
NET AD5 LOC=P37;

NET AD6 LOC=P36;
NET AD7 LOC=P35;
NET A0 LOC=P1; # LOWER BYTE OF ADDRESS
NET A1 LOC=P2;
NET A2 LOC=P3;
NET A3 LOC=P75;
NET A4 LOC=P79;
NET A5 LOC=P82;
NET A6 LOC=P83;
NET A7 LOC=P84;
NET A8 LOC=P58; # UPPER BYTE OF ADDRESS
NET A9 LOC=P56;
NET A10 LOC=P54;
NET A11 LOC=P55;
NET A12 LOC=P53;
NET A13 LOC=P57;
NET A14 LOC=P61;
NET A15 LOC=P34;
NET WR_ LOC=P63; # ACTIVE-LOW WRITE-ENABLE FOR ALL RAMS
NET OE_ LOC=P62; # ACTIVE-LOW OUTPUT-ENABLE FOR ALL RAMS
NET CE_ LOC=P65; # ACTIVE-LOW CHIP-ENABLE FOR XS95 RAM
NET LCE_ LOC=P6; # ACTIVE-LOW CHIP-ENABLE FOR LEFT XSTEND RAM
NET RCE_ LOC=P7; # ACTIVE-LOW CHIP-ENABLE FOR RIGHT XSTEND RAM
2.7 Stereo Codec
The XStend Board has a stereo codec that accepts two analog input channels from jack J9,
digitizes the analog values, and sends the digital values to the XS Board as a serial bit stream.
The codec also accepts a serial bit stream from the XS Board and converts it into two analog
output signals which exit the XStend Board through jack J10.
The codec is configured by placing shunts on the following jumpers:
Table 3:Jumper settings for XStend codec.
Jumper Setting
J11 Placing a shunt on this jumper disables the codec by
holding it in the reset state.
J13, J15 Placing shunts across two of the three pins of these
jumpers selects the digital de-emphasis for different
sampling rates:
0 0 De-emphasis for 32 KHz
0 1 De-emphasis for 44.1 KHz
1 0 De-emphasis for 48 KHz
1 1 De-emphasis off