Hi, I've set a PPI 8255 to my circuit. I've made some condition:
1. WR='1' and RD='0'
2. WR='0' and RD='1'
with CS=A1=A0=x (don't care).

When I make those condition, the output of VCC (26) pin always on logic '1', even I'm not connect it to Power Supply. The only condition to make Vcc pin '0' is to make WR=RD=0.

Is my PPI has broken or it's just a wrong connection ?