FTDI Community
General Category => Discussion - Hardware => Topic started by: JMLsystem on September 03, 2019, 09:59:40 am
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I'm using the FT4222H on the motherboard of our product and i have some questions about it :
1) What is the minimum low time for the RESETN signal before VCCIO rising ?
2) Does the EEPROM chip need to programmed before using the FT4222H ?
Because when my Host access to the FT4222 through the USB port,
in QSPI Master mode (DCNF[1:0]=00 or 11)
i can see the SS0O chip select going low during 1.92µs,
but there are no SCLK clock pulse, no MISO/MOSI/IO[2:3] changes (there are stuck à 0V)
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Hello,
You have contacted our support team via email with these questions.
The answer can be posted here once it's resolved to help other FTDI Community users.
Best Regards,
FTDI Community
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Responses from FTDI technical Support :
1) "Does the EEPROM chip need to programmed before using the FT4222H ?
-> The OTP does not need to programmed before using the FT4222H.
Please evaluate using the UMFT4222EV : this module OTP is not pre-programmed.
2) "What is the minimum low time for the RESETN signal before VCCIO rising ?"
-> The minimum low time is about 5.2us