I'm not sure, but it sounds familiar. Anyway, it's a fully automatic 20mm spanish-made cannon if I recall correctly.
Accourding to the Soldf the PVB302 used a 20 mm canon that was manufactured in Switzerland, today the same canon is used on the Patgb 203A. It also sas that the canons was first used on the Saab 29 Tunnan.
A forgotten vehicle, the ikv 91 (infanterikanonvagn 91). Remember confusing this one with the strf 90 when I was yunger. Designed as a tankkiller it was kind of a failure with only ~200 ex produced. It was taken out of service in the early 90s.