Silicon Laboratories CP2104 User manual

Rev. 0.7 7/13 Copyright © 2013 by Silicon Laboratories CP2104-EK
CP2104-EK
CP2104 EVALUATION KIT USER’SGUIDE
1. Kit Contents
The CP2104 Evaluation Kit contains the following items:
CP2104 Evaluation Board
RS232 Serial Cable
USB Cable
DVD
Quick Start Guide
2. Relevant Documentation
Application notes can be found on the Interface Application Notes page for all fixed-function devices:
www.silabs.com/interface-appnotes.
AN721: CP210x/CP211x Device Customization Guide — Customize the VID, PID, serial number, and
other parameters stored in the CP2104 one-time programmable ROM.
AN197: Serial Communications Guide for CP210x — Programming guide for using the Virtual COM Port
(VCP) drivers.
AN169: USBXpress Programmer’s Guide — Programming guide for using the USBXpress drivers.
AN220: C8051F32x and CP210x USB Driver Customization — VCP or USBXpress driver customization
tool.
AN223: Port Configuration and GPIO for CP210x — Programming guide and DLL for runtime control of
the CP2104 GPIO pins.
AN571: CP210x Virtual COM Port Interface — USB interface details for CP210x devices.
3. Software Setup
The Software Development Kit (SDK) for the CP2104 kit is included on the kit DVD. The latest version of this
installer can also be downloaded from the www.silabs.com/interface-software website. This package includes:
Device Customization Utility (AN721)
Documentation —data sheet, application notes, user’s guide, quick start guide, etc.
CP210x Virtual COM Port (VCP) Drivers
Software — Driver Customization Utility (AN220) and programming examples
The Windows installer should launch automatically after inserting the DVD. For Mac and Linux, browse to the
appropriate directory on the DVD to install the software package. Follow the instructions to install the SDK and
drivers to the system.
3.1. USBXpress Driver Development Kit
The Silicon Laboratories USBXpress ® Development Kit provides a complete host software solution for interfacing to
CP210x devices. No USB protocol or host device driver expertise is required. Instead, a simple, high-level Application
Program Interface (API) for the host software is used to provide complete USB connectivity. The USBXpress
Development Kit includes Windows device drivers, Windows device driver installer, host interface function library
(host API) provided in the form of a Windows Dynamic Link Library (DLL). See Application Note AN169, “USBXpress
Programmer’s Guide” for detailed information on using the USBXpress drivers.
The USBXpress drivers are available here: www.silabs.com/usbxpress.
Click the USBXpress Development Kit link in the Download for Windows 2000/XP/Server 2003/Vista/Win7 section
to download the USBXpress drivers. Run the installer and follow the steps to install the software to the desired

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location. The default installation directory is C:\SiLabs\MCU\USBXpress_SDK.
Further installation instructions for the WinCE drivers can be found in the ReadMe.txt file contained inside the
driver package.
4. CP2104 Hardware Interface
The evaluation board is connected to a PC as shown in Figure 1.
1. Connect one end of the USB cable to a USB Port on the PC.
2. Connect the other end of the USB cable to the USB connector on the
CP2104 evaluation board.
3. Connect one end of the RS232 serial cable to the DB-9 connector on the CP2104 evaluation board .
4. Connect the other end of the RS232 serial cable to the target serial device.
Figure 1. Hardware Setup
CP2104 EK
Serial Device
RS232
CP2104 USB-to-
UART Bridge
USB
1
2
3
4

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5. CP2104 Software Interface
If the Virtual COM Port drivers are used, the CP2104 will appear as a COM port in the Device Manager, as shown
in Figure 2. The CP2104 will always use the lowest available COM port for operation. For instance, if COM ports 1
and 2 are in use by other peripherals and applications, the CP2104 will use COM 3.
The CP2104 functions identically to a COM port from the reference point of both the host application and the serial
device, and it can support serial device control requests defined in the Microsoft Win32®Communications API.
Examples for how to communicate with the device as a serial COM port are included in AN197 on the
www.silabs.com/interface-appnotes page or in the SDK.
If the USBXpress drivers are used, the CP2104 will appear as a USB USBXpress device as shown in Figure 2.
Examples for how to communicate with the device using the USBXpress interface are included in AN169 on the
www.silabs.com/interface-appnotes page.
Figure 2. CP2104 in Device Manager

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6. Evaluation Board
The CP2104 Evaluation Kit includes an evaluation board with a CP2104 device pre-installed for evaluation and pre-
liminary software development. Numerous input/output (I/O) connections are provided to facilitate prototyping using
the evaluation board. Refer to
Figure 3 for the locations of the various I/O connectors.
P1 USB connector for USB interface
P2 DB9 connector for RS232 interface
J1 UART signal access connector
J2, J3 GPIO access connector
J4 Power connector
DS0–DS3 Green GPIO LEDs
DS4 Red SUSPEND indicator LED
Figure 3. CP2104 Evaluation Board with Default Shorting Blocks Installed
6.1. LED Headers (J2, J3)
Connectors J2 and J3 are provided to allow access to the GPIO pins on the CP2104. Place shorting blocks on J2
and J3 to connect the GPIO pins to the four green LEDs DS0–DS3. These LEDs can be used to indicate active
communications through the CP2104. Table 1 shows the LED corresponding to each header position.
6.2. Universal Serial Bus (USB) Interface (P1)
A Universal Serial Bus (USB) connector (P1) is provided to facilitate connections to the USB interface on the
CP2104. See Table 2 for the USB pin definitions.
Table 1. J2 and J3 LED Locations
LED Pins
DS0 J3[3:4]
DS1 J3[1:2]
DS2 J2[3:4]
DS3 J2[1:2]
Table 2. USB Connector Pin Descriptions
Pin # Description
1 VBUS
2D-
3D+
4 GND (Ground)
P2 CP2104
P1
SUSPEND LED
J1
Pin 2
Pin 1 J3
J4
J2 DS3
DS2
DS1
DS0
_________
DS4
RS232
Transceiver

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6.3. UART Signals (P2, J1)
An RS232 transceiver circuit and DB9 connector (P2) are provided on the evaluation board to connect the CP2104
virtual serial port to external serial devices. See Table 3 for the RS232 P2 pin descriptions. The J1 connector is
provided to facilitate direct access to the CP2104’s UART signals. Shorting blocks on J1 are required to connect
the UART signals to P2. See Table 4 for J1 pin descriptions.
6.4. Power Connector (J4)
This header (J4) is included on the evaluation board to provide several power options. The following describes the
function of each pin:
Pins 1–2: Connects CP2104 VIO input (Pin 5) to CP2104 VDD (Pin 6). Remove the shorting block to power
VIO from an external source.
Pins 3–4: Connects the main +3 V net to the CP2104 VDD (Pin 6). The main +3 V net powers the other
components (four green LEDs and RS232 Sipex Part) on the evaluation board.
Table 3. RS232 Pin Descriptions
Pin Signal CP2104
Direction Description
1 DCD Input Data Carrier Detect
2 RXD Input Receive Data
3 TXD Output Transmit Data
4 DTR Output Data Terminal Ready
5 GND Ground
6 DSR Input Data Set Ready
7 RTS Output Request to Send
8 CTS Input Clear to Send
9 RI Input Ring Indicator
Table 4. J1 Pin Descriptions
Pins Signal CP2104
Direction Description
1–2 TXD Output Transmit Data
3–4 RXD Input Receive Data
5–6 DTR Output Data Terminal Ready
7–8 RI Input Ring Indicator
9–10 DCD Input Data Carrier Detect
11–12 DSR Input Data Set Ready
13–14 CTS Input Clear to Send
15–16 RTS Output Request to Send

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7. Schematic
Figure 4. CP2104 Evaluation Board Schematic

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DOCUMENT CHANGE LIST
Revision 0.1 to Revision 0.2
Updated "6.4. Power Connector (J4)" on page 5 to
reflect the updated schematic.
Updated J4 in Figure 4, “CP2104 Evaluation Board
Schematic,” on page 6.
Revision 0.2 to Revision 0.3
Updated "7. Schematic" on page 6.
Revision 0.3 to Revision 0.4
Updated "2.1.1. Virtual COM Port Driver Installation
for Windows" on page 1.
Updated "2.2.1. USBXpress Installation for
Windows" on page 2.
Removed “2.2.2. USBXpress Installation for
Windows 98SE” on page 2.
Revision 0.4 to Revision 0.5
Updated Figure 3 with shorting blocks installed.
Revision 0.5 to Revision 0.6
Updated "3. Software Setup" on page 1.
Revision 0.6 to Revision 0.7
Updated “1. Kit Contents” to change CD-ROM to
DVD.
Added “2. Relevant Documentation”.
Updated “3. Software Setup” to point to the drivers
on the website.
Updated Figure 1 and Figure 2.

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