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Implicit Two-Step Recovery Boot: the Operative Procedures

A recovery boot  (aka TE USB FX2 firmware recovery) is a multi-step boot operation:

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• follow the same procedure of  Cypress Generic USB Device Installation;

• check that EEPROM connection is enabled (EEPROM switch is set in a way to

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• enable EPPROM connection to USB FX2 microcontroler);

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• Cypress firmware update tools and OpenFutNet can read and write the EEPROM:

  1. 1. for example using CyControl (Cypress USB Control Center);

     2. for example using CyConsole (Cypress USB Console);
     3. for example using OpenFutNet recovery boot.

See also Cypress USB Control Center recovery boot and Cypress USB Console recovery boot videos for further information about the procedures to follow.

Implicit Two-Step Recovery Boot: a longer description

In an implicit two-step recovery boot, the user should (the necessary device driver is assumed already installed (Cypress Generic USB Device Installation))

• isolate the FX2 microcontroller's external EEPROM disabling the EEPROM switch;
• use a reset if the the running SW tool is not able to recognize the TE USB FX2 module as a supported device;
• reconnect the FX2 microcontroller's external EEPROM enabling the EEPROM switch;

• give the command to load the desired good firmware into FX2 microcontroller's external EEPROM using CyControl, CyConsole, OpenFutNet (Windows OS, all SW tools using CyAPI.lib or CyUSB.dll) ;

  Info

  The CyConsole's "Lg EEPROM" button, CyControl's "64KB EEPROM" button and OpenFutNet's "Program USB: write IIC EEPROM" button call the loadEEPROM() function. This function is used to program 64-Kbyte EEPROMs. When the button (CyConsole's Lg EEPROM button, CyControl's EEPROM button or OpenFutNet's IIC button) is clicked, the user is prompted to select a (.iic) file to load into the EEPROM. This button first downloads the Vend_Ax.bix file, then sends the 0xA9 vendor request to program the EEPROM.

  The CyConsole/CyControl/OpenFutNet program will load

  1. (hidden/implicit 1) an intermediate good firmware supporting EEPROM programming (normally the 2nd stage bootloader Vend_Ax.hex ) in RAM;

  2. (explicit step 2) the desired good firmware into FX2 microcontroller's external EEPROM using the the intermediate good firmware (2nd stage bootloader Vend_Ax.hex) in RAM.
• use a reset or write the desired good firmware into FX2 microcontroller's RAM using CyControl (Windows OS). If OpenFutNet is used in the step before, the desired good firmware is already written into FX2 microcontroller's RAM.

Using Cypress firmware update tools with generation 2 modules does require a recovery boot, in order to force enumeration as Cypress generic USB device driver.
On the other side, using Cypress firmware update tools with generation 3 modules does not require a recovery boot. This is possible because the original Cypress generic USB device driver (in case of a recovery boot) and the Trenz Electronic USB FX2 device driver ( in case of a regular boot) are both Cypress driver. Trenz Electronic USB FX2 driver derives from the original Cypress generic USB device driver.
EEPROM switch shall always be on during EEPROM programming.
The firmware update procedure is similar for both generations. The following table summarizes the main differences.

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