Hi, I git cloned caravel GitHub in my directory. Then, I opened "user_analog_project_wrapper.mag" in Magic and placed my design in the Caravel Wrapper to manually connect to the pins, but I think two pins are missing in the left corner of the wrapper, gpio_analog[18] and gpio_analog[19]. I need a wrapper with mixed signal pads. The one that is based on the attached picture. Could anyone help me? Thanks

@sepide asgari Do you need bare pins with no esd protection or just analog pins? If you do not need bare pins, I think you can configure the gpios as analog ports on

user_project_wrapper

.

Thank you for your reply. Which one should we use for mixed-signal pads? When I use "user_project_wrapper", metal 4 and metal 5 are reserved for power routing. Since I have used these metals in my own design, it makes many wrong connections. So, I want to use an empty wrapper without any power routing in the middle to have the pin names in the first picture that I sent. Thanks

The default

user_project_wrapper

for

caravel

is just a place holder. Normally, you’d run openlane flow.tcl on

user_project_wrapper

and it will connect the macros and do all the wiring. You can however, do the top level wiring yourself. (I think).

If we place an analog design, which wrapper should we use? Should we use Openlane again for routing? Or can we do it manually? Thanks

The gpio cells have minimum width connections, but the bare analog pads have wider connections. If you need wider output paths,

user_analog_project_wrapper

would be better, I imagine. If it’s just analog signals and you don’t care about parasitics too much, you could probably use

user_project_wrapper

and have openlane route everything. You’d need to create a top level verilog rtl file for the connections.