remove layer from indexing comment of pin-track and track-pin lookup types

Author: soheilshahrouz

vpr/src/route/rr_graph_generation/rr_types.h

@@ -6,23 +6,31 @@
 #include "rr_node_types.h"
 #include "vtr_ndmatrix.h"
 
-/* AA: This structure stores the track connections for each physical pin. Note that num_pins refers to the # of logical pins for a tile and 
+/* This structure stores the track connections for each physical pin. Note that num_pins refers to the # of logical pins for a tile and
  * we use the relative x and y location (0...width and 0...height of the tile) and the side of that unit tile to locate the physical pin. 
  * If pinloc[ipin][iwidth][iheight][side]==1 it exists there... 
  * The alloc_and_load_pin_to_track_map loads up the tracks that connect to each of the *PHYSICAL* pins. Thus, the last dimension of the matrix
  * goes from [0...Fc-1] where Fc is the actual Fc value for that pin. 
  *
  * The matrix should be accessed as follows as a result after allocation in rr_graph.cpp: alloc_pin_to_track_lookup (used by unidir and bidir)
- * [0..device_ctx.physical_tile_types.size()-1][0..num_pins-1][0..width][0..height][0..layer-1][0..3][0..Fc-1] */
+ * [0..device_ctx.physical_tile_types.size()-1][0..num_pins-1][0..width][0..height][0..3][0..Fc-1] */
 typedef std::vector<vtr::NdMatrix<std::vector<int>, 4>> t_pin_to_track_lookup;
 
-/* AA: t_pin_to_track_lookup is alloacted first and is then converted to t_track_to_pin lookup by simply redefining the accessing order.
- * As a result, the matrix should be accessed as follow as a result after allocation in rr_graph.cpp: alloc_track_to_pin_lookup (used by unidir and bidir)
- * [0..device_ctx.physical_tile_types.size()-1][0..max_chan_width-1][0..width][0..height][0..layer-1][0..3]
- * 
- * Note that when we model different channels based on position not axis, we can't use this anymore and need to have a lookup for each grid location. */
+/**
+ * @brief Lookup table from routing tracks to block pins.
+ *
+ * The allocation is done in `alloc_and_load_track_to_pin_lookup()`, and the table becomes
+ * a track-to-pin lookup simply by changing the access order of the underlying data.
+ *
+ * After allocation, the lookup should be accessed in the following index order:
+ * [0..device_ctx.physical_tile_types.size()-1][0..max_chan_width - 1][0..width][0..height][0..3]
+ *
+ * @note When we model different channels based on position not axis,
+         we can't use this anymore and need to have a lookup for each grid location.
+ */
 typedef std::vector<vtr::NdMatrix<std::vector<int>, 4>> t_track_to_pin_lookup;
 
+
 /**
  * @brief Lists detailed information about wire segments.  [0 .. W-1].
  */