Why Do Diagram Tools Struggle with Crossing Arrows? The Sugiyama Framework | Untangling a graph | VLSI Connections | ~12 Min Read | One afternoon, while working through a straightforward CPU subsystem consisting of a CPU, GIC, interconnect, and several peripherals including UART, memory, and Ethernet, I decided to generate a datasheet showing the platform's interfaces and connectivity.The SystemC description was remarkably clear. The structure flowed naturally, and anyone reading the platform configuration could understand the architecture almost instantly. Then I asked a tool to draw it.What emerged was a diagram far more complicated than the design itself. Connections crossed where they didn't need to. Router outputs twisted around each other. A return path sliced diagonally across the page, cutting through unrelated connections. The architecture hadn't changed, but its visual representation had become harder to understand than the source de...