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USB low-full-high speed peripherals Forum Discussions

albr_1058251
Level 1
Level 1

I am using cyusb3014, I wrongly config the FSLC[2:0] to 001, while I want it to be 100 previously, So I wanna know : if I connect a 26MHz Oscillator to the XTALIN pin, Will It work?

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1 Solution
JayakrishnaT_76
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hello,

Please refer to Table 3 - Crystal/Clock Frequency Selection of FX3 datasheet which mentions about the supported configurations for FSLC[2:0]. As per this table, FSLC[2:0] = 001 is not supported by FX3.

In addition to this, please refer to the section Clocking of FX3 datasheet. This section mentions that FX3 allows either a crystal to be connected between the XTALIN and XTALOUT pins or an external clock to be connected at the CLKIN pin. Crystal frequency supported is 19.2 MHz, while the external clock frequencies supported are 19.2, 26, 38.4, and 52 MHz.

So, if your requirement is to use a 26MHz oscillator, then FSLC[2:0] needs to be configured as 101 and the oscillator should be connected to CLKIN pin.

Best Regards,

Jayakrishna

Best Regards,
Jayakrishna

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3 Replies
JayakrishnaT_76
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hello,

Please refer to Table 3 - Crystal/Clock Frequency Selection of FX3 datasheet which mentions about the supported configurations for FSLC[2:0]. As per this table, FSLC[2:0] = 001 is not supported by FX3.

In addition to this, please refer to the section Clocking of FX3 datasheet. This section mentions that FX3 allows either a crystal to be connected between the XTALIN and XTALOUT pins or an external clock to be connected at the CLKIN pin. Crystal frequency supported is 19.2 MHz, while the external clock frequencies supported are 19.2, 26, 38.4, and 52 MHz.

So, if your requirement is to use a 26MHz oscillator, then FSLC[2:0] needs to be configured as 101 and the oscillator should be connected to CLKIN pin.

Best Regards,

Jayakrishna

Best Regards,
Jayakrishna

FSLC[2:0] = 001 is not supported by the reference, but I still need to find a way to make it work.  can I config this through software?

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Hello,

The states of FSLC[2:0] pins are checked by the FX3 ROM Bootloader when the device is connected to the host. It is not possible to configure these pins through software. These pins have to be properly pulled up/pulled down externally depending on your requirement.

Best Regards,

Jayakrishna

Best Regards,
Jayakrishna
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