How does this block diagram convert input current to per unit value?

This is from

Field-Oriented Control of PMSM Using Hall Sensor

openExample("mcb/FocHallExample")

From Current controller subsystem. I couldn't wrap around how this method converts the input current to per unit value when I don't see a division of a base value, like how we analyze transformer problems. Can someone explain to me how this successfully converts the current to per unit value? Or point me to a resource that I can study, because I can't find anywhere online that explains this.

Answer 1

[Walter Roberson]

Input values are multiplied by 2^6. Note that Qu<<6 has the same effect as Vu*2^6 for integer-type values, except that the undefinedness of overflow conditions are expressed slightly different ways.

After that, the sfix32_En17 takes the bits and applies an internal division by 2^17 .

175 * 2^6 --> 11200

11200 / 2^16 --> 0.08544921875

So an input of 175 generates an output of 0.08545