Alias registers with sensible names

interp/interp.py

@@ -1,12 +1,26 @@
+# demonstrate driving low level rp2040 functions from Python by
+# direct register access - see datasheet at 
+# https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf
+# for details
+
 from machine import mem32
 
+# base address of SIO
+SIO_BASE = 0xD0000000
+
+# INTERP0 registers
+INTERP0_ACCUM0 = 0xD0000000 + 0x80
+INTERP0_BASE0 = 0xD0000000 + 0x88
+INTERP0_POP_LANE0 = 0xD0000000 + 0x94
+INTERP0_CTRL_LANE0 = 0xD0000000 + 0xAC
+
 # initialise lane 0 on interp: set that we are using all 32 bits
-mem32[0xD0000000 | 0xAC] = 0x1F << 10
+mem32[INTERP0_CTRL_LANE0] = 0x1F << 10
 
 # set up 9 x table example - write to accum[0] and base[0] registers
-mem32[0xD0000000 | 0x80] = 0
-mem32[0xD0000000 | 0x88] = 9
+mem32[INTERP0_ACCUM0] = 0
+mem32[INTERP0_BASE0] = 9
 
 # read pop register 10 times
 for j in range(10):
-    print(mem32[0xD0000000 | 0x94])
+    print(mem32[INTERP0_POP_LANE0])