FT221XS-R FTDI, FT221XS-R Datasheet - Page 34

• Manufacturer Part Number: FT221XS-R
• Description: USB Interface IC USB to 8 bit SPI / FT1248 IC SSOP-20
• Manufacturer: FTDI

Specifications of FT221XS-R

• Rohs: yes
• Product: USB 2.0
• Data Rate: 12 Mbps, 480 Mbps
• Interface Type: USB
• Operating Supply Voltage: 2.97 V to 5.5 V
• Operating Supply Current: 8.1 mA to 13.1 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SSOP-20
• Tradename: X-Chip

Table 9.1 Default Internal MTP Memory Configuration
9.2 Methods of Programming the MTP Memory
9.2.1 Programming the MTP memory over USB
The MTP memory on all FT-X devices can be programmed over USB. This method is the same as for the
EEPROM on other FTDI devices such as the FT232R. No additional hardware, connections or programming
voltages are required. The device is simply connected to the host computer in the same way that it would
be for normal applications, and the FT_Prog utility is used to set the required options and program the
device.
The FT_Prog utility is provided free-of-charge from the FTDI website, and can be found at the link below.
The user guide is also available at this link.
http://www.ftdichip.com/Support/Utilities.htm#FT_Prog
Additionally, D2XX commands can be used to program the MTP memory from within user applications.
For more information on the commands available, please see the D2XX Programmers Guide below.
http://www.ftdichip.com/Support/Documents/ProgramGuides/D2XX_Programmer's_Guide(FT_000071).p
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9.2.2 Programming the MTP memory over FT1248
In the FT221X device, it is possible to program the MTP memory over its FT1248 interface. This is the
same interface which is used in the normal application of the FT221X and would normally be connected to
a microcontroller (MCU) or FPGA. However, special commands can also be used to access the MTP
memory in the FT221X over the same FT1248 connection, allowing the MCU/FPGA to read and write
locations in the MTP memory. No additional hardware, connections or programming voltages are
required.
Two examples where it may be desired to use the FT1248 interface to write and read the MTP Memory
are given below. In some cases, the application may use both of these possibilities.
DBUS Schmitt Trigger
CBUS Schmitt Trigger
1. To store and retrieve application specific data such as calibration constants in the user area (e.g.
2. To read and write the configuration data (e.g. custom VID, PID, description strings or CBUS
CBUS Drive Current
Load VCP Driver
CBUS slew rate
if the overall application was an analog measurement system). This can avoid the need for an
extra EEPROM chip on the application board.
signal selection to enable signals for battery charging etc) without a USB host. This could allow an
MCU/FPGA to configure the FT221X during production testing of the finished device or even when
in use in the field.
Parameter
Strength
Enable
Enable
CBUS3
Copyright © 2013 Future Technology Devices International Limited
Keep_Awake#
Disabled
Normal
Normal
Value
4mA
Slow
when unplugged. May be used if programming the
Enabling this will load the VCP driver interface for
Prevents the device from entering suspend state
Document No.: FT_000630 Clearance No.: FTDI# 263
MTP memory over the FT1248 interface.
Options are 4mA, 8mA, 12mA, 16mA
Options are normal or Schmitt
Options are normal or Schmitt
Options are slow or fast
the device.
Notes
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