FT201XQ-R FTDI, FT201XQ-R Datasheet - Page 29

• Manufacturer Part Number: FT201XQ-R
• Description: USB Interface IC USB to I2C IC QFN-16
• Manufacturer: FTDI

Specifications of FT201XQ-R

• Rohs: yes
• Product: USB 2.0
• Data Rate: 12 Mbps, 480 Mbps
• Interface Type: I2C, USB
• Operating Supply Voltage: 2.97 V to 5.5 V
• Operating Supply Current: 6.4 mA to 8.65 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-16
• Tradename: X-Chip

FT201X USB I2C SLAVE IC Datasheet
Version 1.3
Document No.: FT_000627 Clearance No.: FTDI# 264
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9
USB and I
C Interfacing
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This section covers the transfer of data from USB to I
C and vice versa.
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Please note that the FT200XD and FT201X are I
C slave devices only and should be interfaced to an I
C
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host (often in a microcontroller or FPGA). If an I
C master is required, please see the FT232H, FT2232H,
FT4232H and FT2232D devices.
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This section covers transfer of data only. The USB and I
C interfaces on the FT200XD and FT201X can
also be used for programming of the MTP memory, which is covered in a separate section.
Throughout this section, the reference FT-X applies to the FT200XD and FT201X devices, as the other
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members of the FT-X family do not have I
C interfaces.
9.1 Host Interface (USB)
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From the host computer’s point of view, the I
C data can be sent and received in the same way as when
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interfacing to one of the standard UART devices such as the FT232R. The FT-X handles the entire I
C
protocol inside the chip and so reading and writing data does not require any special programming from
the PC side. It can be treated as a simple data bridge.
9.1.1 VCP and D2xx Interfaces
Like the other FTDI devices, the host can use D2xx commands or can use a Virtual COM Port (VCP) to
communicate with the device.
D2xx Interface
The D2xx method allows the application software to use the functions in the FTDI D2xx library to
communicate directly with the device. This is a library provided free-of-charge by FTDI and is available
within the driver download files at the link below.
http://www.ftdichip.com/Drivers/D2XX.htm
It includes functions to find the FTDI devices on the system, open a particular device, send data to the
device and read data from the device. Any data written using FT_Write, for example, will be sent to the
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FT-X chip and will be available for the external I
C Master to read. As mentioned above, only the data
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itself needs to be sent as the FT-X handles all of the I
C specific protocol.
There are many other functions available, and full details can be found in the D2xx Programmers Guide.
http://www.ftdichip.com/Support/Documents/ProgramGuides/D2XX_Programmer's_Guide(FT_000071).pd
f
Virtual COM Port Interface
If using the Virtual Com Port (VCP), the device will appear as if it were a real COM port on the computer.
This is useful where an application has already been written to use an RS232 port on the computer as it
allows that application to treat the FT-X as if it were a real COM port. This port can be opened in a
terminal program or a custom application in the same way as a serial port would be opened. Data can
then be sent or received using standard serial / COM port functions.
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No I
C decoding is required as the chip itself handles the I
C protocol. Because of this, even I
C versions
of the FT-X family can be used with the VCP interface. Any data which the host PC sends to the Virtual
COM Port (for example, typed into the terminal window in HyperTerminal) will be sent over USB to the
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FT-X and can then be read by the external I
C Master. Likewise, any data written to the FT-X over I
C will
be sent to the PC where the terminal program will display it.
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Since the FT-X is the I
C slave and does not generate a clock signal, the settings such as baud rate and
handshaking do not have any effect.
Copyright © 2013 Future Technology Devices International Limited
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