EEPROM management

Warning

Writing to the EEPROM can cause very undesired effects if the wrong value is written in the wrong place. You can even essentially brick your FTDI device. Use this function only with extreme caution.

It is not recommended to use this application with devices that use an internal EEPROM such as FT232R or FT-X series, as if something goes wrong, recovery options are indeed limited. FT232R internal EEPROM seems to be unstable, even the official FT_PROG tool from FTDI may fail to fix it on some conditions.

If using a Hi-Speed Mini Module and you brick for FTDI device, see FTDI_Recovery

Supported features

EEPROM support is under active development.

Some features may be wrongly decoded, as each FTDI model implements a different feature map, and more test/validation are required.

The EEPROM API implements the upper API to access the EEPROM content.

EEPROM configuration tool

ftconf.py is a companion script to help managing the content of the FTDI EEPROM from the command line. See the Tools chapter to locate this tool.

usage: ftconf.py [-h] [-i INPUT] [-l {all,raw,values}] [-o OUTPUT] [-V VIRTUAL]
                 [-P VIDPID] [-M EEPROM] [-S {128,256,1024}] [-x] [-X HEXBLOCK]
                 [-s SERIAL_NUMBER] [-m MANUFACTURER] [-p PRODUCT] [-c CONFIG]
                 [--vid VID] [--pid PID] [-e] [-E] [-u] [-v] [-d]
                 [device]

Simple FTDI EEPROM configurator.

positional arguments:
  device                serial port device name

optional arguments:
  -h, --help            show this help message and exit

Files:
  -i INPUT, --input INPUT
                        input ini file to load EEPROM content
  -l {all,raw,values}, --load {all,raw,values}
                        section(s) to load from input file
  -o OUTPUT, --output OUTPUT
                        output ini file to save EEPROM content
  -V VIRTUAL, --virtual VIRTUAL
                        use a virtual device, specified as YaML

Device:
  -P VIDPID, --vidpid VIDPID
                        specify a custom VID:PID device ID (search for FTDI devices)
  -M EEPROM, --eeprom EEPROM
                        force an EEPROM model
  -S {128,256,1024}, --size {128,256,1024}
                        force an EEPROM size

Format:
  -x, --hexdump         dump EEPROM content as ASCII
  -X HEXBLOCK, --hexblock HEXBLOCK
                        dump EEPROM as indented hexa blocks

Configuration:
  -s SERIAL_NUMBER, --serial-number SERIAL_NUMBER
                        set serial number
  -m MANUFACTURER, --manufacturer MANUFACTURER
                        set manufacturer name
  -p PRODUCT, --product PRODUCT
                        set product name
  -c CONFIG, --config CONFIG
                        change/configure a property as key=value pair
  --vid VID             shortcut to configure the USB vendor ID
  --pid PID             shortcut to configure the USB product ID

Action:
  -e, --erase           erase the whole EEPROM content
  -E, --full-erase      erase the whole EEPROM content, including the CRC
  -u, --update          perform actual update, use w/ care

Extras:
  -v, --verbose         increase verbosity
  -d, --debug           enable debug mode

Again, please read the License terms before using the EEPROM API or this script. You may brick your device if something goes wrong, and there may be no way to recover your device.

Note that to protect the EEPROM content of unexpected modification, it is mandatory to specify the -u flag along any alteration/change of the EEPROM content. Without this flag, the script performs a dry-run execution of the changes, i.e. all actions but the write request to the EEPROM are executed.

Once updated, you need to unplug/plug back the device to use the new EEPROM configuration.

It is recommended to first save the current content of the EEPROM, using the -o flag, to have a working copy of the EEPROM data before any attempt to modify it. It can help restoring the EEPROM if something gets wrong during a subsequence update, thanks to the -i option switch.

Most FTDI device can run without an EEPROM. If something goes wrong, try to erase the EEPROM content, then restore the original content.

Option switches

In addition to the Common options switches for PyFtdi tools, ftconf.py support the following arguments:

-c name=value

Change a configuration in the EEPROM. This flag can be repeated as many times as required to change several configuration parameter at once. Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode.

The name should be separated from the value with an equal = sign or alternatively a full column : character.

  • To obtain the list of supported name, use the ? wildcard: -c ?, or -c help to avoid conflicts with some shells

  • To obtain the list of supported values for a name, use the ? or the help wildcard: -c name=help, where name is a supported name.

See CBUS function table for the alternate function associated with each name.

-E

Erase the full EEPROM content including the CRC. As the CRC no longer validates the EEPROM content, the EEPROM configuration is ignored on the next power cycle of the device, so the default FTDI configuration is used.

This may be useful to recover from a corrupted EEPROM, as when no EEPROM or a blank EEPROM is detected, the FTDI falls back to a default configuration.

Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode.

-e

Erase the whole EEPROM and regenerates a valid CRC.

Beware that as -e option generates a valid CRC for the erased EEPROM content, the FTDI device may identified itself as VID:PID FFFF:FFFF on next reboot. You should likely use the –vid and –pid option to define a valid FDTI device USB identifier with this option to ensure the device identifies itself as a FTDI device on next power cycle.

Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode.

Alternatively, use -E option that erase the full EEPROM content including the CRC.

-i

Load a INI file (as generated with the -o option switch. It is possible to select which section(s) from the INI file are loaded, using -l option switch. The values section may be modified, as it takes precedence over the raw section. Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode.

-l <all|raw|values>

Define which section(s) of the INI file are used to update the EEPROM content along with the -i option switch. Defaults to all.

The supported feature set of the values is the same as the one exposed through the -c option switch. Unsupported feature are ignored, and a warning is emitted for each unsupported feature.

-M <model>

Specify the EEPROM model (93c46, 93c56, 93c66) that is connected to the FTDI device. There is no reason to use this option except for recovery purposes, see option -E. It is mutually exclusive with the -S option.

-m <manufacturer>

Assign a new manufacturer name to the device. Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode. Manufacturer names with / or : characters are rejected, to avoid parsing issues with FTDI URLs.

-o <output>

Generate and write to the specified file the EEPROM content as decoded values and a hexa dump. The special - file can be used as the output file to print to the standard output. The output file contains two sections:

  • [values] that contain the decoded EEPROM configuration as key, value pair. Note that the keys and values can be used as configuration input, see option -c.

  • [raw] that contains a compact representation of the EEPROM raw content, encoded as hexadecimal strings.

-p <product>

Assign a new product name to the device. Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode. Product names with / or : characters are rejected, to avoid parsing issues with FTDI URLs.

--pid

Define the USB product identifier - as an hexadecimal number. This is a shortcut for -c product_id

-S <size>

Specify the EEPROM size -in bytes- that is connected to the FTDI device. There is no reason to use this option except for recovery purposes, see option -E. It is mutually exclusive with the -M option.

-s <serial>

Assign a new serial number to the device. Note that without option -u, the EEPROM content is not actually modified, the script runs in dry-run mode. Serial number with / or : characters are rejected, to avoid parsing issues with FTDI URLs.

-u

Update the EEPROM with the new settings. Without this flag, the script runs in dry-run mode, so no change is made to the EEPROM. Whenever this flag is used, the EEPROM is actually updated and its checksum regenerated. If something goes wrong at this point, you may brick you board, you’ve been warned. PyFtdi offers neither guarantee whatsoever than altering the EEPROM content is safe, nor that it is possible to recover from a bricked device.

--vid

Define the USB vendor identifier - as an hexadecimal number. This is a shortcut for -c vendor_id.

-x

Generate and print a hexadecimal raw dump of the EEPROM content, similar to the output of the hexdump -Cv tool.

CBUS function

The following table describes the CBUS pin alternate functions. Note that depending on the actual device, some alternate function may not be available.

Name

Active

Description

TRISTATE

Hi-Z

IO Pad is tri-stated

TXLED

Low

TX activity, can be used as status for LED

RXLED

Low

RX activity, can be used as status for LED

TXRXLED

Low

TX & RX activity, can be used as status for LED

PWREN

Low

USB configured, USB suspend: high

SLEEP

Low

USB suspend, typically used to power down external devices.

DRIVE0

Low

Drive a constant (FT232H and FT-X only)

DRIVE1

High

Drive a constant (FT232H and FT-X only)

GPIO

IO port for CBUS bit bang mode

TXDEN

High

Enable transmit for RS485 mode

CLK48

Output 48 MHz clock (FT232R only)

CLK30

Output 30 MHz clock (FT232H only)

CLK24

Output 24 MHz clock (FT232R and FT-X only)

CLK15

Output 12 MHz clock (FT232H only)

CLK12

Output 12 MHz clock (FT232R and FT-X only)

CLK7_5

Output 7.5 MHz clock (FT232H only)

CLK6

Output 6 MHz clock (FT232R and FT-X only)

BAT_DETECT

High

Battery Charger Detect (FT-X only)

BAT_NDETECT

Low

Inverse signal of BAT_DETECT (FT-X only)

I2C_TXE

Low

Transmit buffer empty (FT-X only)

I2C_RXF

Low

Receive buffer full (FT-X only)

VBUS_SENSE

High

Detect when VBUS is present via the appropriate AC IO pad (FT-X only)

BB_WR

Low

Synchronous Bit Bang Write strobe (FT232R and FT-X only)

BB_RD

Low

Synchronous Bit Bang Read strobe (FT232R and FT-X only)

TIMESTAMP

Toggle signal each time a USB SOF is received (FT-X only)

AWAKE

Low

Do not suspend when unplugged/disconnect/suspsend (FT-X only)

Examples

  • Change product name and serial number

    pyftdi/bin/ftconf.py ftdi:///1 -p UartBridge -s abcd1234 -u

  • List supported configuration parameters

    pyftdi/bin/ftconf.py ftdi:///1 -c ?
  cbus_func_0, cbus_func_1, cbus_func_2, cbus_func_3, cbus_func_4,
  cbus_func_5, cbus_func_6, cbus_func_7, cbus_func_8, cbus_func_9,
  channel_a_driver, channel_a_type, chip, clock_polarity,
  flow_control, group_0_drive, group_0_schmitt, group_0_slew,
  group_1_drive, group_1_schmitt, group_1_slew, has_serial,
  has_usb_version, in_isochronous, lsb_data, out_isochronous,
  power_max, powersave, product_id, remote_wakeup, self_powered,
  suspend_pull_down, type, usb_version, vendor_id

  • List supported configuration values for CBUS0

    pyftdi/bin/ftconf.py ftdi:///1 -c cbus_func_0:?
  AWAKE, BAT_DETECT, BAT_NDETECT, BB_RD, BB_WR, CLK12, CLK24, CLK6,
  DRIVE0, DRIVE1, I2C_RXF, I2C_TXE, GPIO, PWREN, RXLED, SLEEP,
  TIME_STAMP, TRISTATE, TXDEN, TXLED, TXRXLED, VBUS_SENSE

  • Erase the whole EEPROM including its CRC.

    Once power cycle, the device should run as if no EEPROM was connected. Do not use this with internal, embedded EEPROMs such as FT230X.

    pyftdi/bin/ftconf.py -P ffff:ffff ftdi://ffff:ffff/1 -E -u

  • Recover from an erased EEPROM with a valid CRC

    # for a FT4232 device
# note that ffff matches an erased EEPROM, other corrupted values may
# exist, such device can be identified with system tools such as lsusb

pyftdi/bin/ftconf.py -P ffff:ffff ftdi://ffff:ffff/1 -e -u \
    --vid 0403 --pid 6011

  • Configure CBUS: 0 and 3 as GPIOs, then show the device configuration

    pyftdi/bin/ftconf.py ftdi:///1 -v
   -c cbus_func_0:GPIO -c cbus_func_3:GPIO