Cypress CY3640 USB Starter Kit
User’s Guide
Cypress Semiconductor Ver 0.993
Page 10
E. About the Cypress CY3640 USB Starter Kit
Overview
The Cypress CY3640 USB Starter Kit includes a fully functional USB thermometer device, a
Windows95 thermometer application, and a USB Thermometer device driver. Together, these
components allow the user to measure and display temperatures between 0ºC and 70ºC to an
accuracy of ±1ºC.
In addition to being a useful USB device, Cypress has designed the USB Starter Kit to serve as
an easily customizable platform for USB device development using the Cypress CY7C63X0X
family of USB controllers.
Features
The CY3640 has the following features:
The Cypress USB Controller is socketed in a 20-pin socket
It may be removed, reprogrammed, and replaced for easy development of new assembly
code.
Cypress has supplied a bread board area (sea of holes)
This area will accept wire wrap pins and wire wrap sockets. This area will make it easy to
develop additional logic on-board.
A connector for use with standard 40-pin flat-cable connectors has been provided.
All signals from the Cypress USB Controller, which are useful for the development of external
logic, are available at pins on the connector. The signal names are labeled on the top layer of
the board. Pin numbers on the connector are labeled on both the top and bottom layers of the
board to make it easy to wire to the connector.
An identical set of signal vias is placed adjacent to the connector for easy wiring to the
signals.
Connections to external power source
There is a location for an external power supply connector, but the connector is not supplied
with the kit. Individual labeled locations for Vss, USB Vbus (the positive supply of the USB),
and External Vcc are provided on either side of the sea of holes.
LED indicators (Power and Enumeration)
The CY3640 includes two LEDs: a red and a green one. As configured when the CY3640 is
shipped from the factory, the LEDs are used to indicate that power is applied and that the
USB host has enumerated the Cypress USB Thermometer device, respectively.
The anode of each LED is connected to the USB Vbus (positive supply) through a current
limiting resistor. The cathode of each device is connected to three places to allow you to
reconfigure them for your own purposes: a jumper, a pin on the 40-pin connector, and a hole
for installing a wire wrap pin.
The Power LED
The Power LED (as shipped from Cypress) is used to indicate that power (Vbus) from the
USB has been applied. It is connected through a jumper (JP1) and a current limiting resistor
(R4) directly between Vbus and Vss, and will be lit whenever power is applied through the
USB. The user may remove JP1 if desired.
