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when i configure my FPGA (Xylo) normally, It runs the correct speed (24mhz) yet if i configure the boot prom with the very same rbf it will run half speed on start up (12mhz)

any ideas on what i may be doing wrong? (iv noticed you can set the fx2 clk speed 12/24/48, its like even though this is set to 24 when i program the boot prom it resets it self to 12mhz)

im using the FPGAconf 2.12.02


any help would be greatly appreciated as my project is now ready to be run stand alone without a usb umbilical cord connected to it and would be great if it ran 24mhz when it starts up

12MHz is the native speed of the board but you can change it by adding an EEPROM to the FX2 and programming it with this file from the StartupKit.
"EEPROM FX2 change startup clock to 24MHz.bin"

Check also the doc chapter 21.

I see

When i do a search for I2C devices nothing shows up / Trying to program the I2C EEPROM just gives an error

I did notice in the documentation it mentions the FPGA must be configured with a “soft macro” I2C controller.

I could not find any example rbf files to do this.

It has nothing to do with a soft macro I2C controller, what is missing is an I2C EEPROM, you have to either solder one on the board or connect one to the I2C connector. Then you can program it.

I'm trying to do the same thing, except I'd like to set the default to 48MHz.

Can you provide a "EEPROM FX2 change startup clock to 48MHz.bin" I2C EEPROM bin file that I could use for this purpose?

I'd really appreciate it. Thanks.

PS I would use the PLL, but the PPL is already being used to generate two other clocks with speeds incompatible with 48MHz.

Send a request to KNJN, they might have the file you need.