[FSM] Add AXI burst example (#1373)

magma/sum_type.py

@@ -213,7 +213,10 @@ def __init__(self, T):
         # Use elsewhen/otherwise to avoid latch detect issues
         # TODO(leonardt/sum): Enforce that this isn't interleaved with other
         # when/case statements
-        if len(self._value.activated_cases) == self._value.num_tags - 1:
+        if (
+            self._value.num_tags > 1 and
+            len(self._value.activated_cases) == self._value.num_tags - 1
+        ):
             self._when_ctx = otherwise()
         elif self._value.activated_cases:
             self._when_ctx = elsewhen(value.check_tag(T))
@@ -245,7 +248,7 @@ def __new__(mcs, name, bases, namespace):
         tag_len = 0
         for key, value in namespace.items():
             if isinstance(value, int):
-                tag_len = max(tag_len, value.bit_length())
+                tag_len = max(tag_len, value.bit_length(), 1)
 
         if tag_len:
             tag_map = {}

magma/syntax/fsm.py

@@ -69,7 +69,7 @@ def __exit__(self, exc_type, exc_value, exc_tb):
         self._when_ctx.__exit__(exc_type, exc_value, exc_tb)
 
 
-def loop(start, end, step=1):
+def loop(start, end, step=1, iter_cond=None):
     with m.no_when():
         end_reg = m.Register(type(end))()
         end_reg.I @= end_reg.O
@@ -79,9 +79,12 @@ def loop(start, end, step=1):
         i.I @= i.O + step
     i.I @= start
     m.wait()
-    # TODO: We explicitly override after wait, otherwise defautl value will set
+    # TODO: We explicitly override after wait, otherwise default value will set
     # start, can we avoid this?
     i.I @= i.O + step
+    if iter_cond is not None:
+        with m.when(~iter_cond):
+            i.I @= i.O
     when = m.when(end_reg.O < i.O)
     curr_fsm = _FSM_STACK.peek()
     when.exit_stack.callback(

tests/conftest.py

@@ -1,4 +1,5 @@
 from magma.config import config as magma_config
+import pytest
 
 
 def pytest_configure(config):
@@ -8,3 +9,10 @@ def pytest_configure(config):
     #
     # magma_config.use_namer_dict = True
     magma_config.use_uinspect = True
+
+
+@pytest.fixture
+def use_namer_dict():
+    magma_config.use_namer_dict = True
+    yield
+    magma_config.use_namer_dict = False

tests/test_syntax/gold/test_fsm_axi_burst.mlir

@@ -0,0 +1,222 @@
+module attributes {circt.loweringOptions = "locationInfoStyle=none,omitVersionComment"} {
+    hw.module @Memory(in %RADDR: i32, in %CLK: i1, out RDATA: i32) {
+        %0 = hw.constant 0 : i32
+        %1 = hw.constant 0 : i32
+        %2 = hw.constant 0 : i1
+        %4 = sv.reg name "coreir_mem4294967296x32_inst0" : !hw.inout<!hw.array<4294967296xi32>>
+        %5 = sv.array_index_inout %4[%RADDR] : !hw.inout<!hw.array<4294967296xi32>>, i32
+        %3 = sv.read_inout %5 : !hw.inout<i32>
+        %6 = sv.array_index_inout %4[%0] : !hw.inout<!hw.array<4294967296xi32>>, i32
+        sv.alwaysff(posedge %CLK) {
+            sv.if %2 {
+                sv.passign %6, %1 : i32
+            }
+        }
+        hw.output %3 : i32
+    }
+    hw.module @AXIBurstReader(in %ARVALID: i1, in %ARADDR: i32, in %ARSIZE: i3, in %ARLEN: i8, in %RREADY: i1, in %CLK: i1, out ARREADY: i1, out RVALID: i1, out RLAST: i1, out RDATA: i32) {
+        %1 = hw.struct_create (%0) : !hw.struct<tag: i1>
+        %3 = sv.reg name "Register_inst0" : !hw.inout<!hw.struct<tag: i1>>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %3, %1 : !hw.struct<tag: i1>
+        }
+        %5 = hw.constant 0 : i1
+        %4 = hw.struct_create (%5) : !hw.struct<tag: i1>
+        sv.initial {
+            sv.bpassign %3, %4 : !hw.struct<tag: i1>
+        }
+        %2 = sv.read_inout %3 : !hw.inout<!hw.struct<tag: i1>>
+        %6 = hw.struct_extract %2["tag"] : !hw.struct<tag: i1>
+        %7 = hw.constant 0 : i1
+        %8 = comb.icmp eq %6, %7 : i1
+        %9 = hw.constant 0 : i1
+        %12 = sv.reg name "Register_inst1" : !hw.inout<i1>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %12, %10 : i1
+        }
+        %13 = hw.constant 0 : i1
+        sv.initial {
+            sv.bpassign %12, %13 : i1
+        }
+        %11 = sv.read_inout %12 : !hw.inout<i1>
+        %14 = hw.constant 1 : i1
+        %17 = sv.reg name "Register_inst2" : !hw.inout<i1>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %17, %15 : i1
+        }
+        sv.initial {
+            sv.bpassign %17, %13 : i1
+        }
+        %16 = sv.read_inout %17 : !hw.inout<i1>
+        %20 = sv.reg name "Register_inst3" : !hw.inout<i8>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %20, %18 : i8
+        }
+        %21 = hw.constant 0 : i8
+        sv.initial {
+            sv.bpassign %20, %21 : i8
+        }
+        %19 = sv.read_inout %20 : !hw.inout<i8>
+        %24 = sv.reg name "len_reg" : !hw.inout<i8>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %24, %22 : i8
+        }
+        %25 = hw.constant 0 : i8
+        sv.initial {
+            sv.bpassign %24, %25 : i8
+        }
+        %23 = sv.read_inout %24 : !hw.inout<i8>
+        %28 = sv.reg name "Register_inst4" : !hw.inout<i8>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %28, %26 : i8
+        }
+        sv.initial {
+            sv.bpassign %28, %21 : i8
+        }
+        %27 = sv.read_inout %28 : !hw.inout<i8>
+        %29 = hw.constant 1 : i8
+        %30 = comb.add %27, %29 : i8
+        %31 = hw.constant 0 : i8
+        %34 = sv.reg name "Register_inst5" : !hw.inout<i1>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %34, %32 : i1
+        }
+        sv.initial {
+            sv.bpassign %34, %13 : i1
+        }
+        %33 = sv.read_inout %34 : !hw.inout<i1>
+        %35 = hw.constant 1 : i8
+        %36 = comb.add %27, %35 : i8
+        %38 = hw.constant -1 : i1
+        %37 = comb.xor %38, %RREADY : i1
+        %39 = comb.icmp ult %19, %27 : i8
+        %42 = sv.reg name "addr_reg" : !hw.inout<i32>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %42, %40 : i32
+        }
+        %43 = hw.constant 0 : i32
+        sv.initial {
+            sv.bpassign %42, %43 : i32
+        }
+        %41 = sv.read_inout %42 : !hw.inout<i32>
+        %44 = comb.extract %27 from 0 : (i8) -> i1
+        %45 = comb.extract %27 from 1 : (i8) -> i1
+        %46 = comb.extract %27 from 2 : (i8) -> i1
+        %47 = comb.extract %27 from 3 : (i8) -> i1
+        %48 = comb.extract %27 from 4 : (i8) -> i1
+        %49 = comb.extract %27 from 5 : (i8) -> i1
+        %50 = comb.extract %27 from 6 : (i8) -> i1
+        %51 = comb.extract %27 from 7 : (i8) -> i1
+        %52 = hw.constant 0 : i1
+        %53 = hw.constant 0 : i1
+        %54 = hw.constant 0 : i1
+        %55 = hw.constant 0 : i1
+        %56 = hw.constant 0 : i1
+        %57 = hw.constant 0 : i1
+        %58 = hw.constant 0 : i1
+        %59 = hw.constant 0 : i1
+        %60 = hw.constant 0 : i1
+        %61 = hw.constant 0 : i1
+        %62 = hw.constant 0 : i1
+        %63 = hw.constant 0 : i1
+        %64 = hw.constant 0 : i1
+        %65 = hw.constant 0 : i1
+        %66 = hw.constant 0 : i1
+        %67 = hw.constant 0 : i1
+        %68 = hw.constant 0 : i1
+        %69 = hw.constant 0 : i1
+        %70 = hw.constant 0 : i1
+        %71 = hw.constant 0 : i1
+        %72 = hw.constant 0 : i1
+        %73 = hw.constant 0 : i1
+        %74 = hw.constant 0 : i1
+        %75 = hw.constant 0 : i1
+        %76 = comb.concat %75, %74, %73, %72, %71, %70, %69, %68, %67, %66, %65, %64, %63, %62, %61, %60, %59, %58, %57, %56, %55, %54, %53, %52, %51, %50, %49, %48, %47, %46, %45, %44 : i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1, i1
+        %77 = comb.add %41, %76 : i32
+        %78 = hw.constant 1 : i8
+        %79 = comb.sub %23, %78 : i8
+        %80 = comb.icmp eq %27, %79 : i8
+        %81 = hw.constant 0 : i1
+        %82 = hw.constant 0 : i32
+        %85 = sv.reg name "size_reg" : !hw.inout<i3>
+        sv.alwaysff(posedge %CLK) {
+            sv.passign %85, %83 : i3
+        }
+        %86 = hw.constant 0 : i3
+        sv.initial {
+            sv.bpassign %85, %86 : i3
+        }
+        %84 = sv.read_inout %85 : !hw.inout<i3>
+        %91 = sv.reg : !hw.inout<i1>
+        %10 = sv.read_inout %91 : !hw.inout<i1>
+        %92 = sv.reg : !hw.inout<i32>
+        %40 = sv.read_inout %92 : !hw.inout<i32>
+        %93 = sv.reg : !hw.inout<i3>
+        %83 = sv.read_inout %93 : !hw.inout<i3>
+        %94 = sv.reg : !hw.inout<i8>
+        %22 = sv.read_inout %94 : !hw.inout<i8>
+        %95 = sv.reg : !hw.inout<i1>
+        %87 = sv.read_inout %95 : !hw.inout<i1>
+        %96 = sv.reg : !hw.inout<i1>
+        %15 = sv.read_inout %96 : !hw.inout<i1>
+        %97 = sv.reg : !hw.inout<i8>
+        %18 = sv.read_inout %97 : !hw.inout<i8>
+        %98 = sv.reg : !hw.inout<i8>
+        %26 = sv.read_inout %98 : !hw.inout<i8>
+        %99 = sv.reg : !hw.inout<i1>
+        %32 = sv.read_inout %99 : !hw.inout<i1>
+        %100 = sv.reg : !hw.inout<i32>
+        %88 = sv.read_inout %100 : !hw.inout<i32>
+        %101 = sv.reg : !hw.inout<i1>
+        %89 = sv.read_inout %101 : !hw.inout<i1>
+        %102 = sv.reg : !hw.inout<i1>
+        %90 = sv.read_inout %102 : !hw.inout<i1>
+        %103 = sv.reg : !hw.inout<i1>
+        %0 = sv.read_inout %103 : !hw.inout<i1>
+        sv.alwayscomb {
+            sv.bpassign %91, %9 : i1
+            sv.bpassign %95, %9 : i1
+            sv.bpassign %96, %9 : i1
+            sv.bpassign %97, %19 : i8
+            sv.bpassign %98, %30 : i8
+            sv.bpassign %99, %9 : i1
+            sv.bpassign %101, %9 : i1
+            sv.bpassign %102, %9 : i1
+            sv.bpassign %100, %82 : i32
+            sv.bpassign %92, %41 : i32
+            sv.bpassign %93, %84 : i3
+            sv.bpassign %94, %23 : i8
+            sv.bpassign %103, %6 : i1
+            sv.if %8 {
+                sv.bpassign %91, %ARVALID : i1
+                sv.if %11 {
+                    sv.bpassign %92, %ARADDR : i32
+                    sv.bpassign %93, %ARSIZE : i3
+                    sv.bpassign %94, %ARLEN : i8
+                    sv.bpassign %95, %14 : i1
+                    sv.bpassign %96, %14 : i1
+                    sv.if %16 {
+                        sv.bpassign %97, %23 : i8
+                        sv.bpassign %98, %31 : i8
+                        sv.bpassign %99, %14 : i1
+                        sv.if %33 {
+                            sv.bpassign %98, %36 : i8
+                            sv.if %37 {
+                                sv.bpassign %98, %27 : i8
+                            }
+                            sv.if %39 {
+                                sv.bpassign %100, %77 : i32
+                                sv.bpassign %101, %14 : i1
+                                sv.bpassign %102, %80 : i1
+                            } else {
+                                sv.bpassign %103, %81 : i1
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        %104 = hw.instance "mem" @Memory(RADDR: %88: i32, CLK: %CLK: i1) -> (RDATA: i32)
+        hw.output %87, %89, %90, %104 : i1, i1, i1, i32
+    }
+}

tests/test_syntax/test_fsm.py

@@ -114,5 +114,64 @@ class Foo(m.Circuit):
                 io.O @= 0xDEED
                 state.next @= State.DONE
 
-    m.compile("build/test_fsm_wait_loop", Foo, output="mlir-verilog")
+    m.compile("build/test_fsm_wait_loop", Foo, output="mlir")
     assert check_gold(__file__, "test_fsm_wait_loop.mlir")
+
+
+def test_fsm_axi_burst(use_namer_dict):
+    class Resp(m.Enum):
+        OKAY = 0b00
+        EXOKAY = 0b01
+        SLVERR = 0b10
+        DECERR = 0b11
+
+    class Burst(m.Enum):
+        FIXED = 0b00
+        INCR = 0b01
+        WRAP = 0b10
+        RESERVED = 0b11
+
+    class State(m.FSMState):
+        INIT = 0
+
+    class AXIBurstReader(m.Circuit):
+        io = m.IO(
+            ARREADY=m.Out(m.Bit),
+
+            ARVALID=m.In(m.Bit),
+            ARADDR=m.In(m.Bits[32]),
+            ARSIZE=m.In(m.Bits[3]),
+            ARLEN=m.In(m.Bits[8]),
+
+            RREADY=m.In(m.Bit),
+
+            RVALID=m.Out(m.Bit),
+            RLAST=m.Out(m.Bit),
+            RDATA=m.Out(m.Bits[32]),
+        ) + m.ClockIO()
+        addr_reg = m.Register(m.UInt[32])()
+        size_reg = m.Register(m.Bits[3])()
+        len_reg = m.Register(m.UInt[8])()
+
+        mem = m.Memory(2 ** 32, m.Bits[32], read_only=True)()
+        io.RDATA @= mem.RDATA
+
+        io.ARREADY @= 0
+        io.RLAST @= 0
+        io.RVALID @= 0
+        with m.fsm(State, init=State.INIT) as state:
+            with m.case(State.INIT):
+                m.wait_until(io.ARVALID)
+                addr_reg.I @= io.ARADDR
+                size_reg.I @= io.ARSIZE
+                len_reg.I @= io.ARLEN
+                io.ARREADY @= 1
+                m.wait()
+                with m.loop(0, len_reg.O, iter_cond=io.RREADY) as i:
+                    mem.RADDR @= addr_reg.O + m.zext_to(i, 32)
+                    io.RVALID @= 1
+                    io.RLAST @= i == (len_reg.O - 1)
+                state.next @= State.INIT
+
+    m.compile("build/test_fsm_axi_burst", AXIBurstReader, output="mlir")
+    assert check_gold(__file__, "test_fsm_axi_burst.mlir")