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XC9536 ISP Demo Board

XAPP078 April, 1997 (Version 1.0) Summary

XC9536 ISP Demo Board
Application Note
XAPP078 April, 1997 (Version 1.0) Summary
The demo board described in this application note is a tool for demonstrating the In-System Programming (ISP) capabilities of the XC9500 CPLD family. Xilinx Family XC9500
Introduction
Using EZTag, the ISP download software from Xilinx, you can easily program any XC9500 device while it is attached to a PC board. EZTag allows you to program, verify, erase, and functionally test XC9500 devices. The schematic of the ISP demonstration board, using an XC9536 device, is shown in Figure 1.
these locations to provide connection points for plug-on jumpers or wire-wrapping. The proto-typing area on the customer version has 299 holes (13 columns x 23 rows) for attaching additional circuitry. The holes are .038" diameter on .10" centers. Two pair of these holes are connected to +5V and GND along the left side of the prototyping area. Figure 2 shows the ABEL code used to describe a Johnson Shift Counter created and implemented with Xilinx XABELCPLD software. You can use this reference design as-is, or you can modify the design as required. Figure 3 shows the same design done in VHDL, using the Xilinx Foundation software.
Design Description
There are two versions of this demo board as described below. Both versions use a 555 surface-mount timer, with resistor and capacitor values set for 14 Hz operation. This oscillator clocks a simple test design (a Johnson counter) implemented in the XC9536 this counter drives LEDs used to verify operation. The two versions of the demo board are: · FAE version - The FAE XC9536 ISP Demo Board comes in a plastic case which holds the Printed Circuit Board (PCB) and a 9V battery, 5V regulator, filter capacitor, and the on-off switch. Customer version - The Customer XC9536 ISP Demo Board is the same as the FAE version except for the addition of a prototyping area. Also, the case, battery, 5V regulator, filter capacitor, and the on-off switch are not installed on the customer version.
Parts List
The FAE version of the ISP Demo Board comes complete with all parts installed. The Customer version does not include the power supply components which can be purchased from Digi-Key as shown in Table 1. Table 1: Digi-Key Parts List Qty. 1 1 1 Description DPDT Switch, right angle 5V, 1A, low dropout reg. 22uf, 16V, Tantalum cap. Digi-Key Part Ref. No. SW1 EG1909 U2 LM2940CT-5.0 C4 P2040
Both PCBs come with a 44-pin VQFP XC9536 device with two bypass capacitors, (8) LEDs with current limiting resistors, and a header for attaching the JTAG Cable. Both versions of the ISP Demo Board allow attachment of an external regulated +5V power supply via the pads at J2. If a +5V regulator is installed at location U2 with a 22uF (or larger) filter capacitor at C4, an external DC voltage of 7V to 12V can be applied at location J3. This is where the 9V battery is attached on the FAE version. The PCB will accept either a DPDT switch or a permanent jumper at location SW1. The switch is used to connect or disconnect an external DC voltage from the +5V regulator. All pins of the XC9536 device are connected to throughhole pads on the PCB, numbered 1 to 44. Header rows of.025" square posts (on .10" centers) can be installed at
Digi-Key Corporation is located at 701 Brooks Ave. South, Thief River Falls, MN 56701-0677, Tel: 800-344-4539, Fax: 218-681-3380, (http://www.digikey.com). The customer version of the PCB is designed to fit into a SERPAC plastic case, Model H-65 AC. This case can be purchased from SERPAC, 619 Commercial Ave., Covina, CA 91723, Tel: 818-331-0517, Fax: 818-331-8584 (http://www.serpac.com).
XAPP078 April, 1997 (Version 1.0)
XC9536 ISP Demo Board
SW1 60mA ON J3 OFF +9V U2 J2 +5V 9V BATTERY
C2 0.1uF
LM2940
R1 R2 470 R3 470 R4 470 R5 470 470
C1 0.1uF
J1 VCC GND TCK TDO TDI TMS
XC9536
R6 470 R7 R8 470 470
GND TRIG OUT
VCC DISCH THRES
C3 .047uF
RESET CONT
TLC555
Figure 1: ISP Demo Board Schematic
XAPP078 April, 1997 (Version 1.0)
Declarations
/ / GCK1 on XC9536 CPLD / / LED / / LED / / LED / / LED / / LED / / LED / / LED / / LED / / LED Bus Declaration
end jcounter
Figure 2: ABEL Code for the Johnson Counter
XAPP078 April, 1997 (Version 1.0)
XC9536 ISP Demo Board
- Can use attributes to assign pin locations in Foundation VHDL attribute pinnum of Dout:signal is "p13, 14, 16, 18, 19, 20, 21, 22" end jcounter
Figure 3: VHDL Code for the Johnson Counter
XAPP078 April, 1997 (Version 1.0)