[Tool] Add illustrative comments to tileable rr_graph generator
@@ -821,7 +821,34 @@ RRGSB build_one_tileable_rr_gsb(const DeviceGrid& grids,
opin_grid_side[1] = NUM_SIDES;
}
- /* Add IPIN nodes from adjacent grids: the 4 grids sitting on the 4 corners of the Switch Block */
+ /* Add IPIN nodes from adjacent grids: the 4 grids sitting on the 4 corners of the Switch Block
+ *
+ * - The concept of top/bottom side of connection block in GSB domain:
+ *
+ * | Grid[x][y+1] |
+ * | BOTTOM side |
+ * +-----------------------+
+ * |
+ * v
+ * +-----------------------+
+ * | TOP side |
+ * | X- Connection Block |
+ * | BOTTOM side |
+ * +-----------------------+
+ * ^
+ * |
+ * +-----------------------+
+ * | TOP side |
+ * | Grid[x][y] |
+ *
+ * - The concept of top/bottom side of connection block in GSB domain:
+ *
+ * ---------------+ +---------------------- ... ---------------------+ +----------------
+ * Grid[x][y+1] |->| Y- Connection Block Y- Connection Block |<-| Grid[x+1][y+1]
+ * RIGHT side | | LEFT side ... RIGHT side | | LEFT side
+ * --------------+ +---------------------- ... ---------------------+ +----------------
+ *
+ */
for (size_t side = 0; side < rr_gsb.get_num_sides(); ++side) {
SideManager side_manager(side);
size_t ix;
