2017-07-25 06:40 PM
Data sheet for STM32F303 Vih specification indicates;
1. TC and TTa I/O = 0.445*VDD + 0.398
2. FT and FTf I/O = 0.5*VDD + 0.2
3. All I/Os except BOOT0 = 0.7*VDD.
Item 3 seems to contradict 1 and 2. Can this be clarified?
2017-07-25 10:34 PM
The footnote says it: 1 and 2 are based on simulations, 3 is the value against which the ports are tested in production.
JW
2017-07-26 12:24 PM
Dears,
we confirm it. There is no contradiction. we test all our devices at factory before we ship to customers at 0.7*VDD; However we give design guidelines based on simulations and so we relax a bit the worst case testing. It is a matter of Guarantee we provide to end customers.
Here is a picture for illustration on STM32F4 series, but similar as other products to understand what means the Guarantee we provide.
Cheers,
STOne-32