Updating and enumerating  the EEPROM on the SX2 Development Board  without the FX Board Attached.

Question: How to update and enumerate the EEPROM on the SX2 Development Board  without the FX Board Attached ?

 

Answer:

The EEPROM on the SX2 Development Board does not contain a default load. We do have some sample loads that you can write to the EEPROM which will allow the SX2 to enumerate on its own. These EEPROM loads are installed in the directory C:\Cypress\USB\Examples\Sx2\eeprom images after installing the Development Kit software.

Included in that directory is a readme file with a short description of each EEPROM load and brief directions for writing to the EEPROM. In summary the steps are the following:

1. Unplug both boards from the USB, remove the SX2 from the FX, and remove the EEPROM from the FX.

2. Remove the EEPROM from the SX2, install it on the FX, and make sure that there is a jumper on JP9. The EEPROM that comes with the SX2 Development Kit is 64K. Make sure there is no jumper on JP8 in order to read and write to a large, 64K EEPROM.

3. Plug in the FX board to the USB it should come up in Development Manager as "Cypress EZ-USB (2235) - EEPROM missing".

4. Start control panel, click the "Download" button, browse to the Vend_Ax.hex file in the Cypress\USB\Examples\EzUsb\Vend_Ax\ directory, and click on the "Open" button. This will load the vend_ax firmware to the FX.

5. The next two step aren't necessary all the time but it will provide a check to make sure the EEPROM is written to correctly. On the far right side of the "Vend Req" line, delete the contents of the "Hex Bytes" field, type in the value "FE", select "0 Out" in the "Dir" drop down list, and then change the value of the "Length" field to "1".


6. The "Req" field should default to the value "0xA2". Click on the "Vend Req" button to write the value "FE" to the EEPROM. The message area should display "Vendor Request" and on the next line "0000 FE".

7. Read back the first byte of the EEPROM. Select "1 In" in the "Dir" drop down list and click on the "Vend Req" button. The message area should display "Vendor Request" and on the next line "0000 FE".

8. The next step is to write the SX2 firmware to the EEPROM. Click on the "EEPROM" button, browse to the Sx2_C4.iic file in the Cypress\USB\Examples\Sx2\eeprom images\ directory, and click on the "Open" button. This will write the Sx2_C4 firmware to the EEPROM. The message area should display "Vendor Request" and on the next line "0000 C4 CB 80 C4 06 00 B4 04 82 00 00 00".

9. Read back the bytes of the EEPROM. The last command should have changed the "Length" field value to 12; leave it at that value. Select "1 In" in the "Dir" drop down list and click on the "Vend Req" button. The message area should display "Vendor Request" and on the next line "0000 C4 CB 80 C4 06 00 B4 04 82 00 00 00".

10. The EEPROM is now programmed correctly with the SX2 firmware. Remove the EEPROM from the FX and install it on the SX2. Again, assuming a 64K EEPROM, make sure that there is no jumper on JP4. Some other jumpers to check on the SX2 are:

JP3 should have a jumper across pins 1 and 2

JP7 should not have a jumper

All other jumpers should have a jumper across pins 1 and 2







11. Plug in the SX2 to the USB. In Windows Device Manager it should display as "Cypress EZ-USB SX2 Development Board".