Move organization, documentation of jump table op codes

and how they modify indicies to class level.

fpgalib/dac.py

@@ -1172,6 +1172,23 @@ class DAC_Build15(DAC_Build8):
     19  d[1]
     ...
     33  d[15]
+
+    Table documenting how each op code can move the sram, jump table index
+
+    OP    | BEHAVIOR
+    ------------------------------------------------------------------------
+    IDLE  | increment sram_idx and increment jt_idx
+    NOP   | increment sram_idx and increment jt_idx
+    CHECK | move sram_idx and jt_idx OR increment sram_idx and jt_idx
+    JUMP  | move sram_idx and jt_idx
+    CYCLE | move sram_idx and jt_idx OR increment sram_idx and jt_idx
+    END   | no next entry
+
+    Attributes:
+        increment_ops (list[jump_table.Operation]): Jump table op codes that can
+            increment the sram index, jump table index
+        jump_ops (list[jump_table.Operation]): Jump table op codes that can
+            jump the sram index, jump table index
     """
 
     HAS_JUMP_TABLE = True
@@ -1205,6 +1222,15 @@ class DAC_Build15(DAC_Build8):
     MONITOR_0 = 5
     MONITOR_1 = 10
 
+    increment_ops = (
+        jump_table.IDLE, jump_table.NOP, jump_table.CHECK,
+        jump_table.CYCLE
+    )
+
+    jump_ops = (
+        jump_table.CHECK, jump_table.JUMP, jump_table.CYCLE
+    )
+
     @classmethod
     def convert_from_address(cls, x_ns):
         """ Convert a from address from ns to SRAM index.
@@ -1480,17 +1506,8 @@ def make_jump_table(cls, jt_entries, counters=None, start_address_ns=0):
         We verify that jump table commands are not executed too frequently. We
         check when our current command executes, and compare to execution of
         the next command. The next command depends on the specifics of the
-        current command, arguments and conditions. We document all commands
-        below.
-
-        OP    | BEHAVIOR
-        ------------------------------------------------------------------------
-        IDLE  | increment sram_idx and increment jt_idx
-        NOP   | increment sram_idx and increment jt_idx
-        CHECK | move sram_idx and jt_idx OR increment sram_idx and jt_idx
-        JUMP  | move sram_idx and jt_idx
-        CYCLE | move sram_idx and jt_idx OR increment sram_idx and jt_idx
-        END   | no next entry
+        current command, arguments and conditions. See attributes increment_ops,
+        jump_ops.
 
         :param list[jump_table.JumpEntry] jt_entries: JT entries
         :param list[int] counters: counter values, or None for all 0s
@@ -1499,21 +1516,10 @@ def make_jump_table(cls, jt_entries, counters=None, start_address_ns=0):
         :rtype: jump_table.JumpTable
         """
 
-        # these entries can increment both idx
-        increment_idx = (
-            jump_table.IDLE, jump_table.NOP, jump_table.CHECK,
-            jump_table.CYCLE
-        )
-
-        # these entries can move both idx
-        jump_idx = (
-            jump_table.CHECK, jump_table.JUMP, jump_table.CYCLE
-        )
-
         # no two opcodes executed within JT_MIN_CLK_CYCLES_BETWEEN_OPCODES
         for k, jt_entry in enumerate(jt_entries):
             # first pass we check all increment cases
-            if type(jt_entry.operation) in increment_idx:
+            if isinstance(jt_entry.operation, cls.increment_ops):
                 sram_idx = jt_entry.from_addr
                 next_jt_idx = k + 1
                 next_from_addr = jt_entries[next_jt_idx].from_addr
@@ -1523,7 +1529,7 @@ def make_jump_table(cls, jt_entries, counters=None, start_address_ns=0):
                                      "executed too closely in time"
                                      .format(jt_entry))
             # second pass we check all jump cases
-            if type(jt_entry.operation) in jump_idx:
+            if isinstance(jt_entry.operation, cls.jump_ops):
                 sram_idx = jt_entry.to_addr
                 # take off 1 as first entry is always NOP (self.toString)
                 next_jt_idx = jt_entry.operation.jump_index - 1