Standalone

Boundary Scan Test (BST)

with

Xilinx FPGA board

using

XJTAG XJLink2 Controller

Lorenzo Electronics, LLC

Goal

• In order to broaden the commercial JTAG controllers that are supported by LE1200/1201 Automatic Test Equipment, an XJTAG XJLink2 was acquired thanks to XJTAG's free trial program.

• Existing LE1200/1201 system software are enhanced to handle XJLink2.

• Only low level XJLink2 API will be used.

• The new LE1201 should pass the existing test setups.

Lorenzo Electronics, LLC

Standalone BST on FPGA

• In this test, Xilinx FPGA chip (center) 4-wire JTAG pins and ground wires are connected XJTAG XJLink2 JTAG portcontroller (right).

• Other FPGA pins connected to LCD control/data bus are controlled by a test program writing Lorenzo-XJLink2 on the LCD display via the associated boundary scan cells.

Lorenzo Electronics, LLC

sysout screen for a paused test execution

• BST execution sysout screen lists the test pattern numbers as well as the associated test program source lines.

• Boundary scan pins connected to the LCD data bus are groupedtogether with the group name: data. Setting up data bus with anASCII character followed by the pulsing of write signal will latch the character into the LCD display.

Lorenzo Electronics, LLC

Snippet of a BST output file (*.csv)

• Record detailed tri-ctrl/output cells driving states and captured input cells logic states for each test pattern.

• Highlighted spreadsheet column CU shows FPGA pin IO_AB4 tri-ctrl/output cells, #547 and #548 respectively, are in active driving states. It's the write signal writing to the LCD one character every 3 test patterns.

• The column to the left, column CT, indicates the same FPGA pin input cell check state of X. Test program has opted to ignore the captured input cell logic state.

Lorenzo Electronics, LLC

• To ensure that the BST fault detection capability, Microchip Technology Inc. Explorer 16 MPU development board is tested with LE1201 and XJLink2 controller.

• Previously developed test program pass the MPU boundary scan test – without change or re-compilation.

• Fault insertion tests successfully detect the faulty MPU pin.

Lorenzo Electronics, LLC