Trying to program Evil Mad Scientist's Peggy 2 board without their Library. The board drives a LED Matrix with
- Source 74HC154 Decoder
- Sink STP16CPSO5 LED Sink Driver
What has me confused is the 74HC154 Outputs can only have one output set to Low at at time. See table below. This means all but one row is "on". Isn't this backwards? Shouldn't all outputs be low except one that is high? Selecting what row you want on, rather than selecting what row you want off. It looks more like the 74HC154 is a Sink. Thanks.