Cypress WirelessUSB MTK User manual

WirelessUSB™
Manufacturing Test Kit
User’s Guide
Cypress Semiconductor
3901 North First Street
San Jose, CA 95134
408-943-2600
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April 28, 2005

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1. INTRODUCTION
The WirelessUSBTM Manufacturing Test Kit (MTK) is designed to
allow Cypress’ customers to test their WirelessUSB products, in a
manufacturing environment, without the use of expensive RF test
equipment.
The highly integrated nature of the WirelessUSB radio device is
such that there is very little that can go wrong in the assembly
process. The device itself is tested before it leaves the Cypress
factory. There are only a few critical components on the customer’s
board that affect the operation of the radio. Most of the likely
assembly level failures (missing components, open/cold solder
joints, and pin-to-pin shorts) will cause a large reduction in
transmitted power or receive sensitivity, if the unit functions at all.
As such, a simple functionality test at maximum range would
eliminate most bad units.
To keep from having to test each unit over a long distance, and to
prevent interference between multiple units that may be on the test
floor simultaneously, the MTK is designed to simulate a limit-of-
operation condition using shielded Test Fixture and enclosure.

2. KIT DESCRIPTION
The MTK contains the following items.
• MTK Test Fixture
• 12” SMA to SMA coaxial cable
• 24” SMA to SMA coaxial cable
• SMA-F to SMA-F adapter
• (6) Fixed 50 ohm attenuators: 1dB, 2dB, 4dB, 7dB, 15dB,
and 30dB
• SMA 2.4GHz antenna
• Power supply transformer
• CD-ROM with Firmware Source and documentation
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See Photo #1 – Manufacturing Test Kit Contents, below.
Not included but required for use are: the Device Under Test (DUT)
and an anechoic RF test chamber, sized appropriately for the DUT,
with SMA pass-through connectors.
Optional, not included, equipment includes: a variable 50-ohm
attenuator for calibration, an SMA torque wrench, a computer to
download configuration and/or test start commands and, optionally,
log test results, as well as an RS-232 serial cable or USB-to-serial
adapter cable for connecting the computer to the 9-pin D connector
of the MTK Test Fixture.

<Photo #1 – Manufacturing Test Kit Contents>
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3. HARDWARE SETUP
1) Attach the supplied antenna to the SMA pass-through connector of the test
chamber.
o Use the SMA pass-through that is furthest away from the sides of the
chamber if there is more than one.
o Orient the antenna at either 0 degrees or 90 degrees. (It is very important
that the relative position and orientation of the fixed antenna and the DUT be
kept the same for all tests. These can greatly affect the signal strength.)
o See Photo #2 – Fixed Antenna Mounting Example.
2) Attach one coaxial cable to the matching SMA on the outside of the chamber.
o Be sure to connect to the same pass-through that has the antenna installed.
3) Attach the other cable to the SMA on the MTK Test Fixture.
o Please use an appropriate SMA torque wrench on all SMA connections or
tighten finger tight, to avoid damaging the connectors. It is important that the
connections are tight enough that good contact is made. Loose connections
can greatly impact the repeatability of the test.
4) Place fixed or variable attenuators between the two cables.
o See the Appendix C, below for determination of the correct attenuation.
o If using the supplied fixed attenuators, use the female-to-female adapter to
connect the male end of the attenuators to the cable.
5) (Optional) Attach a serial cable (not included) between the MTK test fixture
and computer.
o If a computer will be used for set up or testing, attach it to the serial port with
a serial cable or a USB-to-serial adapter cable (not included).
o See Appendix B for the default setting of the serial port on the test fixture.
6) Insert power plug into the MTK test fixture.
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o The MTK Test Fixture will go through a power-on self-check, which will light
all of the LED indicators. Once the green PASS light is lit, the tester is ready
for use or to receive serial commands.

Fixed attenuator to extend
antenna beyond foam. Or use
SMA-M to SMA-F extender.
<Photo #2 – Fixed Antenna Mounting Example>
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<Photo #3 – Completed Installation>
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4. EXECUTING THE STANDARD TEST
The Standard Test is defined by sending a number of packets over
one or more channels. The bit errors are counted and compared
against an error threshold number and the pass/fail result is
displayed. See Appendix B for instructions on changing the
Standard Test configuration.
Once the test environment is set up, put the device to be tested into
manufacturing test mode and place it in the shielded container.
The device under test (DUT) should respond to the Standard Test
executed by the Tester.
Note that the foam in some shielded test boxes is conductive. The
bare DUT board (if testing a bare PCB) should be placed in a
fixture, not directly on the foam of the box. This will also help
ensure that the DUT to antenna alignment is the same from test to
test, which can make a very large difference in signal strength at
the DUT. See photo #4 below:
<Photo #4 – DUT Fixture>
Press the START button on the Tester. The BUSY light should
come on for a short time. If the test is successful, then the PASS
light will come on when the test is completed. If the test exceeded
the error threshold settings, the Tester will indicate test failure by
lighting the FAIL light.

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APPENDIX A – FIRMWARE
1. FIRMWARE OVERVIEW
The MTK test firmware is divided into two parts, the Test Fixture
Firmware and the DUT Test Code. The DUT Test Code is a small
bit of additional code that resides in the DUT memory and can be
accessed only by placing the DUT into a special test mode. (See
below for more details.) Once in test mode, the DUT in the test
chamber exchanges packets with the Test Fixture. The data
packet from the Test Fixture to the DUT is checked for errors by the
DUT and the error count recorded. The DUT then sends a data
packet back to the Test Fixture that includes the error count
information. The Test Fixture uses this information, as well as
information it collects about errors in the received data packet from
the DUT, to determine if the test passes or fails.
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2. DUT TEST CODE
All packets received by the Device-Under-Test (DUT) are “echoed”
with the addition of an added byte that contains the count of invalid
bits for the received packet. Extra bytes in packets that are larger
than what the DUT can support are ignored. Received packets of
the correct length are then parsed for possible RF command
packets.
The RF command packets exchanged between the MTK Tester
and the MTK DUT contain two or more bytes. The first byte
contains the command type and the remaining bytes contain the
parameter value. All commands are executed after the received
packets are “echoed”.
The DUT Manufacturing Test code adds approximately 500-800
bytes depending on the device and firmware version.
The method to enter the Manufacturing Test Mode varies
depending on the device and firmware version. The CY4632 RDK
Bridge will enter the Manufacturing Test Mode when an SE1
condition (both D+ and D- are held high) is detected during power-
on on all firmware versions from 1.2 and higher. The CY4632 RDK
Mouse and Keyboard uses a compile time define to enter the test
mode by detecting a specific grounded pin or a special key