Parasit pulse on reset when Scaffold is initialized with init_ios=False

[mmouchous-ledger]

A parasit pulse is observed when the trigger output of I2C command is set as the input of a PGEN, and the Scaffold has been initialized with the init_ios option not set to True.

Code like:

        scaffold = Scaffold()
        scaffold.i2c.trigger >> self.scaffold.d2
        pgen = self.scaffold.pgen0
        pgen.start << self.scaffold.d2
        pgen.count = 1
        pgen.delay = pgen.delay_min
        pgen.width = 5e-6
        pgen.out >> self.scaffold.d3
        scaffold.power.restart_dut()
        scaffold.i2c.write(b"abc", trigger=True)

Makes two pulses to appear at some times.

        scaffold = Scaffold(init_ios=True)

Makes only one pulse to appear.

It may also not appear on real first execution of the script (eg with hard reset of the scaffold with the physical button)