DLP-USB245M User Manual
The DLP-USB245M-G is the 2nd generation, lead free version of DLP Design’s USB adapter. This device adds
extra functionality to it’s DLP-USB1 predecessor with a reduced component count and a new low price.
DLP-USB245M FEATURES
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Send / Receive Data over USB at up to 1 M Bytes /
sec
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384 byte FIFO Transmit buffer / 128 byte FIFO
receive buffer for high data throughput
Simple interface to CPU or MCU bus
No in-depth knowledge of USB required as all USB
Protocol is handled automatically within the module
FTDI’s Virtual COM port drivers eliminate the need
for USB driver development in most cases.
Integrated 3.3v Regulator – No External Regulator
Required
Integrated Power-On-Reset circuit
Integrated 6MHz – 48Mhz clock multiplier PLL
USB Bulk or Isocronous data transfer modes
4.4v - 5.25v Single Supply taken directly from the
USB port
UHCI / OHCI / EHCI host controller compatible
USB 1.1 and USB 2.0 compatible
USB VID, PID, Serial Number and Product
Description
Strings stored in on-board EEPROM.
EEPROM programmable on-board via USB
VIRTUAL COM PORT ( VCP ) DRIVERS for
Windows 98 and Windows 98 SE
Windows 2000 / ME / XP
Windows CE **
MAC OS-8 and OS-9
MAC OS-X
Linux 2.40 and greater
D2XX ( USB Direct Drivers + DLL S/W Interface )
Windows 98 and Windows 98 SE
Windows 2000 / ME / XP
APPLICATION AREAS
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Rapid Prototype Development
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USB ISDN and ADSL Modems
High Speed USB PDA Interface
USB Interface for Digital Cameras
USB Interface for MP3 players
High Speed USB Instrumentation
USB Smart Card Readers
Set Top Box (S.T.B.) PC-USB interface
USB Hardware Modems
USB Wireless Modems
USB Bar Code Readers
DLP-USB245M-G USB to FIFO Parallel Interface Module
[ ** = In planning or under development ]
Copyright © DLP Design 2002
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DLP-USB245M User Manual
GENERAL DESCRIPTION
The DLP-USB245M provides an easy cost-effective method
of transferring data to / from a peripheral and a host at up to
8 Million bits (1-Megabyte) per second. Its simple FIFO-like
design makes it easy to interface to any microcontroller or
microprocessor via IO ports.
To send data from the peripheral to the host computer
simply write the byte wide data into the module when TXE#
is low. If the (384 byte) transmit buffer fills up or is busy storing the previously written byte, the device takes TXE#
high in order to stop further data from being written until some of the FIFO data has been transferred over USB to the
host.
When the host sends data to the peripheral over USB, the device will take RXF# low to let the peripheral know that at
least one byte of data is available. The peripheral then reads the data until RXF# goes high indicating no more data is
available to read.
By using FTDI’s virtual COM Port drivers, the peripheral looks like a standard COM Port to the application software.
Commands to set the baud rate are ignored – the device always transfers data at its fastest rate regardless of the
application’s baud rate setting. The latest versions of the drivers are available for download from DLP Design’s
website at http://www.dlpdesign.com.
APPLICATION NOTES
USB devices transfer data in packets. If data is to be sent from the PC, a packet is built up by the application program
and is sent via the device driver to the USB scheduler. This scheduler puts a request onto the list of tasks for the USB
host controller to perform. This will typically take at least 1 millisecond to execute because it will not pick up the new
request until the next ‘ USB Frame’ (the frame period is 1 millisecond).
There is therefore a sizeable overhead (depending on your required throughput) associated with moving the data from
the application to the USB device. If data is sent ‘byte at a time’ by an application, this will severely limit the overall
throughput of the system as a whole.
It must be stressed that in order to achieve maximum throughput, application programs should send or receive data
using buffers and not individual characters.
Copyright © DLP Design 2002
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DLP-USB245M User Manual
DRIVER SOFTWARE
FTDI’s VCP (Virtual COM Port) driver executable files are provided royalty-free on the condition that they are only
used with designs incorporating an FTDI device (ie the FT245BM and DLP-USB245M). The latest version of the
drivers can be downloaded from dlpdesign.com or ftdichip.com.
The VCP driver download file is a combined set of drivers for Windows ‘98, Windows ME and Windows 2000/XP.
Unzip the file to a blank floppy disk or folder on your PC. The drivers can co-exist on the same floppy disk or folder
since the INF files determine which set of drivers to load for each operating system version. Once loaded, the VCP
drivers allow your application software, running on the host PC, to communicate with the DLP-USB245M as though it
were connected to a COM (RS-232) port.
In addition to VCP drivers, FTDI’s “D2XX Direct Drivers” for Windows offer an alternative solution to the VCP drivers
that allows application software to interface with the FT245BM device using a DLL instead of a Virtual Com Port. The
architecture of the D2XX drivers consists of a Windows WDM driver that communicates with the FT245BM device via
the Windows USB Stack and a DLL that interfaces the Application Software (written in VC++, C++ Builder, Delphi,
VB etc...) to the WDM driver. An INF installation file, uninstaller program and D2XX programmers guide complete the
package
The D2XX Direct Drivers add support for simultaneous access and control of multiple FT245BM devices. The
Extended Open function (FT_OpenEx ) allows the device to be opened either by it’s Product Description or by Serial
Number, both of which can be programmed to be unique. The List Devices function (FT-ListDevices) allows the
application software to determine which devices are currently available for use, again by product description or by
serial number.
Several new features have been recently added to the D2XX drivers. Functions are provided to program the
EEPROM (FT_EE_Program), and read the EEPROM (FT_EE_Read). Unused space in the EEPROM is called the
User Area (EEUA), and functions are provided to access the EEUA. FT_EE_UASize gets its size, FT_EE_UAWrite
writes data into it, and FT_EE_UARead is used to read its contents.
Download FTDI Application Notes AN232-03, AN232-05, AN232-06, and AN232-07 for detailed instructions on how to
install and remove the drivers.
Copyright © DLP Design 2002
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DLP-USB245M User Manual
EEPROM WRITE UTILITY
The DLP-USB245M has the option to accept manufacturer-specific information that is written into the 93C46
EEPROM. Parameters that can be programmed include the VID and the PID identifiers, the manufacturer’s product
string and a serial number.
FTD2XXST is the latest EEPROM serializer and testing utility for the FT245BM device. It replaces the VCP based
232Prog utility. FTD2XXST is based on the new D2XX drivers and will work on Win ‘98, Win ME and Win 2000/
XP platforms. You must install the latest release of the D2XX drivers in order to run this application. Refer to the
SER200.PDF guide that is included in the EEPROM Write Utility’s download zip file for details on how to use the
serializer.
If you have VCP drivers installed on the PC that is to perform the EEPROM write process you must uninstall these
drivers using the uninstaller program (included with the driver files) and install the D2XX drivers prior to running the
serializer utility.
QUICK START GUIDE
This guide requires the use of a Windows 98/2000 PC that is equipped with a USB port.
1. Download the DLL version of the device drivers from either dlpdesign.com or ftdichip.com. Unzip the drivers onto
a blank floppy disk or into a folder on the hard drive.
2. Download the serializer program from either dlpdesign.com or ftdichip.com. Unzip the package and place it in a
folder on the hard drive.
3. Select a power source for the DLP-USB245M module via pins 10, 11, and 12. Be sure to pull the RESET# pin
high (pin 3).
4. Connect the DLP-USB245M board to the PC via a standard, 6-foot USB cable. This action initiates the loading
of the USB drivers. When prompted, select the folder where the DLL version of the device drivers were stored
Copyright © DLP Design 2002
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DLP-USB245M User Manual
in step one. Windows will then complete the installation of the device drivers for the DLP-USB245M board. The
next time the DLP-USB245M module is attached, the host PC will immediately load the correct drivers without any
prompting. Reboot the PC if prompted to do so.
5. Run the serializer program and write the VID (0403), PID (6001), a description string of your choosing and
manufacturers ID as instructed in the instruction manual that was downloaded with the serializer software.
Terminate the serializer program and disconnect the DLP-USB245M board from the USB cable. Wait 10 seconds
and reconnect the DLP-USB245M board. Reboot the PC if instructed to do so.
NOTE 1 - The DLP-USB245M comes pre-programmed with a default VID and PID. Step 5 is optional and only
required if different VID/PID codes are required.
NOTE 2 – The “Test” button on the serializer program is intended for use with the DLP-USB232M module (and
FT232BM device) and will fail if used with the DLP-USB245M module. The “Read” function will work and will
present the contents of the EEPROM as well as the serial number and description strings stored in the EEPROM.
At this point the DLP-USB245M is ready for use. Note that the DLP-USB245M will appear non-responsive if data sent
from the host PC is not read from the FT245BM device by an attached microcontroller/microprocessor/DSP/FPGA/
etc…
Copyright © DLP Design 2002
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