update description of register assignment

qick_lib/qick/asm_v1.py

@@ -594,13 +594,13 @@ class QickProgram(AbsQickProgram):
                 "upper": 0b1010, "lower": 0b0101
                 }
 
-    # To make it easier to configure pulses these special registers are reserved for each channel's pulse configuration.
+    # To make it easier to configure pulses, special registers are reserved for each channel's pulse configuration.
     # In each page, register 0 is hard-wired with the value 0.
-    # In page 0 we reserve the following additional registers:
-    # 13, 14 and 15 for loop counters, 16 for the trigger bits.
-    # Pairs of channels share a register page.
-    # The flat_top pulse uses some extra registers.
-
+    # Each channel reserves 10 registers (the flat_top pulse uses some extra registers).
+    # All registers for a channel go on the same page, with registers assigned at the end of the page:
+    #   so a page with 2 channels will assign registers 12 through 21 and 22 through 31.
+    # In page 0 we only put one channel, to make space for the following additional registers:
+    # 13, 14 and 15 for loop and shot counters, 16 for the trigger bits, 17 through 21 for NDAveragerProgram loop counters.
 
     gentypes = {'axis_signal_gen_v4': FullSpeedGenManager,
                 'axis_signal_gen_v5': FullSpeedGenManager,