--- /dev/null
+ Packed Shift Mode Diagram
+ -------------------------
+
+ Plane 0 Plane 1
+ /-----------------^-----------------\ /-----------------^-----------------\
+ 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
++---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
+| | | | | | | | | | | | | | | | | | | | | | | |
++---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
+ | | | | | | | | | | | | | | | |
+ \ | \ | \ | \ | \ | \ | \ | \ |
+3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | | 3 2 | |
+[][][][] [][][][] [][][][] [][][][] [][][][] [][][][] [][][][] [][][][]
+ | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0 | | 1 0
+ | \ | \ | \ | \ | \ | \ | \ | \
+ | | | | | | | | | | | | | | | |
++---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
+| | | | | | | | | | | | | | | | | | | | | | | |
++---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+ +---+---+
+ 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
+ \-----------------v-----------------/ \-----------------v-----------------/
+ Plane 2 Plane 3
+
+ <------- Direction of Shift
+