USB controller has three resets going in,
called preset_n, pwrup_rst_n, and aresetn.
- preset_n comes from the mod_g_rst_n input coming from LPSC
- pwrup_rst_n is PWRUP_RST_N register bit in the USB wrapper module
(USB3P0SS_W1). This reset has to be deasserted before accessing controller registers. The
default value for pwrup_rst_n is 0 (reset asserted). This reset goes to the default
asserted state when mod_g_rst_n reset is asserted.
- areset_n comes from PWRUP_RST_N register bit, but the deassertion is
synchronized to ACLK.