I am on a tangent to improve my understanding of the PSOC power pins, notation, and uses. I have bee studying AN61290 "PSoC 3 and PSoC 5LP" Hardware Design Considerations" as well as some reference designs provided with the various development kits and data sheets.
Clarity and/or confirmation on items in yellow/red highlight would be highly appreciated:
VDDA and VCCA are analog supply pins. What is the difference between the two?
VDDD and VCCD are digital supply pins What is the difference between the two?
VSSA analog ground pins??
VSSD digital ground pins??
VDDIO0, VDDIO1, VDDIO2, VDDIO3 digital supply pins supporting various supply domains i.e. 1.8V, 3.3V. 5V must be less than or equal to VSSA
In document NO CY8C58LP_0010-84932_0E
1. All VDDIOx pins are supplied by VDDD. I think I am fine with this assuming all I/O are in the same digital domain but if they were on different domains then each domain would benefit from its own respective ground at least upto the tie in point no?
2. VSSD is shown having a separate supply source on PIN 66 but then tied to ground on PIN 87 (Page 8 TQFP) is this simply a decoupling here??
3. Is the idea that VSSD pins are scattered throughout the PSoC to provide routing and place options?
4. Intended difference between VSSD and VDDD in this particular reference i.e. VDDD is shown from one source while VSSD is shown from another ?? Why? For some reason I am under the impression that VSSD is digital ground but here it is shown to have a source connection....so clearly I am confused here :)
In drawing CY8CKIT-014 PSoC 5 FirstTouch Starter Kit
1. All VSSD pins are tied to ground??? Is this just because it is a starter kit thus cost was an issue and no attempt to separate analog/digital supply was needed in this design?
Sorry if this is long winded but I really want to sort through all these power pins on the PSoC. Its a maze for me! I am not really a power guru as you can probably tell.