a new protocol of china fast power charger spec. UFCS.

[392625227]

a new protocol decoder of china fast power charger spec. UFCS. full files under https://github.com/392625227/UFCS-protocol-compare-with-USB-PD.

[kamocat]

Hi Edison Ren,
Thank you for your contribution. To help me review this, please:

• provide an English translation of the UFCS specification
• create a pull request to sigrok-dumps for the signal capture ufcs_pv.sr.

Also, I want to ask about the stacked decoder. You chose to stack on top of the UART decoder, but it's not really UART-based. From your README:

The physical layer of UFCS is the UART serial port. Almost all MCUs have their own UART serial port hardware, which makes product development very simple. However, USB-PD adopts BMC encoding, which simply means that 1 and 0 are represented by the width of the pulse, and the high level of the signal is only about 1V, which requires a hardware comparator, which increases the cost.

This sounds like each UART bytes each represents a single bit, as in HDQ. Would it make more sense to measure the bit-width directly, as the SDQ decoder does?