diff --git a/firmware/rtl/raster/raster_cmds.vh b/firmware/rtl/raster/raster_cmds.vh
new file mode 100644
index 0000000..f49c425
--- /dev/null
+++ b/firmware/rtl/raster/raster_cmds.vh
@@ -0,0 +1,19 @@
+/* Make sure there are no gaps! The code generator will not work
+ * correctly.
+ */
+`define RASTER_NOOP 0
+`define RASTER_MAX_SAMPLES 1
+`define RASTER_MAX_LINES 2
+`define RASTER_SETTLE_TIME 3
+`define RASTER_DX 4
+`define RASTER_DY 5
+`define RASTER_ARM 6
+`define RASTER_USED_ADCS 7
+`define RASTER_STEPS_PER_SAMPLE 8
+`define RASTER_RUNNING 9
+
+`define RASTER_WRITE_BIT (1 << (`RASTER_CMD_WID - 1))
+
+`define RASTER_CMD_WID 8
+
+`define RASTER_DATA_WID 32