Update ALU, added more ops

1 files changed, 135 insertions, 74 deletions

diff --git a/hdl/core.py b/hdl/core.py
index 17e2b33..655af68 100644
--- a/hdl/core.py
+++ b/hdl/core.py
@@ -1,6 +1,7 @@
 from multiprocessing import dummy
 from amaranth import *
 from amaranth.sim import Simulator, Settle, Delay
+from enum import Enum, unique
 
 from utils import cmd
 
@@ -78,23 +79,44 @@ from utils import cmd
 
 #         return m
 
+@unique
+class AluOpCodes(Enum):
+    add = 0
+    addc = 1
+    sub = 2
+    subc = 3
+    bit_and = 4
+    bit_or = 5
+    bit_xor = 6
+    bit_nor = 7
+    lleft = 8
+    lright = 9
+    aright = 10
+    set_bit = 11
+    clear_bit = 12
+    umult = 13
+    smult = 14
+    udiv = 15
+    sdiv = 16
+
 class ALU(Elaboratable):
     def __init__(self, sim=False):
         self.in1 = Signal(32, reset_less=True)
         self.in2 = Signal(32, reset_less=True)
+        self.c_in = Signal(1)
         self.out = Signal(32, reset_less=True)
         self.op = Signal(4, reset_less=True)
 
         self.tmp = Signal(33, reset_less=True)
-        self.signed_op = Signal(1, reset_less=True)
 
-        self.carry = Signal(1, reset_less=True)
+        self.c_out = Signal(1, reset_less=True)
         self.overflow = Signal(1, reset_less=True)
         self.zero = Signal(1, reset_less=True)
-        self.sign = Signal(1, reset_less=True)
+        self.neg = Signal(1, reset_less=True)
+        self.odd = Signal(1, reset_less=True)
 
         self.sim = sim
-        self.ports = [self.in1, self.in2, self.op, self.out, self.carry, self.overflow, self.zero, self.sign]
+        self.ports = [self.in1, self.in2, self.op, self.c_in, self.out, self.c_out, self.overflow, self.zero, self.neg]
 
     def elaborate(self, platform=None):
         m = Module()
@@ -105,38 +127,73 @@ class ALU(Elaboratable):
             m.d.sync += dummy.eq(~dummy)
 
         with m.Switch(self.op):
-            with m.Case(0b0000):
+            with m.Case(AluOpCodes.add.value):
                 m.d.comb += self.tmp.eq(self.in1 + self.in2)
-            with m.Case(0b0010):
-                m.d.comb += self.tmp.eq(self.in1.as_signed() + self.in2.as_signed())
-                m.d.comb += self.signed_op.eq(1)
-            with m.Case(0b0001):
+
+            with m.Case(AluOpCodes.addc.value):
+                m.d.comb += self.tmp.eq(self.in1 + self.in2 + self.c_in)
+
+            with m.Case(AluOpCodes.sub.value):
                 m.d.comb += self.tmp.eq(self.in1 - self.in2)
-            with m.Case(0b0011):
-                m.d.comb += self.tmp.eq(self.in1.as_signed() - self.in2.as_signed())
-                m.d.comb += self.signed_op.eq(1)
-            with m.Case(4):
+
+            with m.Case(AluOpCodes.subc.value):
+                m.d.comb += self.tmp.eq(self.in1 + (~self.in2 + self.c_in))
+
+            with m.Case(AluOpCodes.bit_and.value):
                 m.d.comb += self.tmp.eq(Cat(self.in1 & self.in2, 0))
-            with m.Case(5):
+
+            with m.Case(AluOpCodes.bit_or.value):
                 m.d.comb += self.tmp.eq(Cat(self.in1 | self.in2, 0))
-            with m.Case(6):
+
+            with m.Case(AluOpCodes.bit_xor.value):
                 m.d.comb += self.tmp.eq(Cat(self.in1 ^ self.in2, 0))
-            with m.Case(7):
-                m.d.comb += self.tmp.eq(Cat(self.in1 << self.in2[0:5], 0))
-            with m.Case(8):
-                m.d.comb += self.tmp.eq(Cat(self.in1 >> self.in2[0:5], 0))
-            with m.Case(9):
-                m.d.comb += self.tmp.eq(Cat(self.in1.as_signed() >> self.in2[0:5], 0))
+            
+            with m.Case(AluOpCodes.bit_nor.value):
+                m.d.comb += self.tmp.eq(Cat(~(self.in1 | self.in2), 0))
+
+            with m.Case(AluOpCodes.lleft.value):
+                m.d.comb += self.tmp.eq(Cat(self.in1, 0) << self.in2[0:5])
+
+            with m.Case(AluOpCodes.lright.value):
+                tmp2 = Signal(33)
+                m.d.comb += tmp2.eq(Cat(0, self.in1) >> self.in2[0:5])
+                m.d.comb += self.tmp.eq(Cat(tmp2[1:33], tmp2[0]))   # move shifted bit to carry bit
+
+            with m.Case(AluOpCodes.aright.value):
+                tmp2 = Signal(33)
+                m.d.comb += tmp2.eq(Cat(0, self.in1).as_signed() >> self.in2[0:5])
+                m.d.comb += self.tmp.eq(Cat(tmp2[1:33], tmp2[0]))   # move shifted bit to carry bit
+
+            with m.Case(AluOpCodes.set_bit.value):
+                m.d.comb += self.tmp.eq(Cat(self.in1 | (1 << self.in2[0:5]), 0))
+
+            with m.Case(AluOpCodes.clear_bit.value):
+                m.d.comb += self.tmp.eq(Cat(self.in1 & ~(1 << self.in2[0:5]), 0))
+
+            with m.Case(AluOpCodes.umult.value):
+                m.d.comb += self.tmp.eq(Cat(self.in1[0:16] * self.in2[0:16], 0))
+            
+            with m.Case(AluOpCodes.smult.value):
+                m.d.comb += self.tmp.eq(Cat(self.in1[0:16].as_signed() * self.in2[0:16].as_signed(), 0))
+            
+
+            # bad juju, 
+            # TODO: come back and check this will work
+            # with m.Case(AluOpCodes.udiv.value):
+            #     m.d.comb += self.tmp.eq(Cat(self.in1 // self.in2, 0))
+            
+            # with m.Case(AluOpCodes.sdiv.value):
+            #     m.d.comb += self.tmp.eq(self.in1.as_signed() // self.in2.as_signed())   # for some reason I have not confirmed, signed div can yield a 33 bit number, acording to amaranth
+
             with m.Case():
-                m.d.comb += self.signed_op.eq(0)
                 m.d.comb += self.tmp.eq(0)
         
-        m.d.comb += self.carry.eq(self.tmp[32])
+        m.d.comb += self.c_out.eq(self.tmp[32])
         m.d.comb += self.overflow.eq(self.tmp[32] ^ self.tmp[31])
-        m.d.comb += self.sign.eq(self.tmp.as_signed() < 0)
-        m.d.comb += self.zero.eq(self.out == 0)
-
         m.d.comb += self.out.eq(self.tmp[0:32])
+        m.d.comb += self.neg.eq(self.out.as_signed() < 0)
+        m.d.comb += self.zero.eq(self.out == 0)
+        m.d.comb += self.odd.eq(self.out[0])
         
         return m
 
@@ -144,111 +201,115 @@ def test_alu(filename="alu.vcd"):
     dut = ALU(sim=True)
 
     def proc1():
-        def sub_proc(val1, val2):
+        def sub_proc(val1, val2, c_in=0):
             yield dut.in1.eq(val1)
             yield dut.in2.eq(val2)
+            yield dut.c_in.eq(c_in)
             yield
             yield Settle()
 
-        # test unsigned addition
-        yield dut.op.eq(0b0000)
+        # test addition
+        yield dut.op.eq(AluOpCodes.add.value)
         yield from sub_proc(27, 13)
         out = yield dut.out
         assert 27 + 13 == (out), f'ERROR: {out} != {27 + 13}'
 
-        # test signed addition
-        yield dut.op.eq(0b0010)
-        yield from sub_proc(-11, 43)
+        # test addition with carry
+        yield dut.op.eq(AluOpCodes.addc.value)
+        yield from sub_proc(11, 43, 1)
         out = yield dut.out.as_signed()
-        assert -11 + 43 == out, f'ERROR: {out} != {-11 + 43}'
+        assert 11 + 43 + 1 == out, f'ERROR: {out} != {11 + 43 + 1}'
 
-        # test unsigned subtraction
-        yield dut.op.eq(0b0001)
+        # test subtraction
+        yield dut.op.eq(AluOpCodes.sub.value)
         yield from sub_proc(25, 13)
         out = yield dut.out
         assert 25 - 13 == out, f'ERROR: {out} != {25 - 13}'
         
-        # test signed subtraction
-        yield dut.op.eq(0b0011)
-        yield from sub_proc(25, -13)
+        # test subtraction with carry
+        yield dut.op.eq(AluOpCodes.subc.value)
+        yield from sub_proc(25, -13, 0)
+        out = yield dut.out.as_signed()
+        assert 25 + 13 -1 +0 == out, f'ERROR: {out} != {25 + 13 -1 +0}'
+
+        # test subtraction with carry
+        yield dut.op.eq(AluOpCodes.subc.value)
+        yield from sub_proc(25, -13, 1)
         out = yield dut.out.as_signed()
-        assert 25 + 13 == out, f'ERROR: {out} != {25 + 13}'
+        assert 25 + 13 -1 +1 == out, f'ERROR: {out} != {25 + 13 -1 +1}'
 
-        # test unsigned logical and
-        yield dut.op.eq(4)
+        # test binary and
+        yield dut.op.eq(AluOpCodes.bit_and.value)
         yield from sub_proc(0b10101011, 0b01010101)
         out = yield dut.out
         assert 0b00000001 == out, f'ERROR: {out} != {0b00000001}'
 
-        # test unsigned logical or
-        yield dut.op.eq(5)
+        # test binary or
+        yield dut.op.eq(AluOpCodes.bit_or.value)
         yield from sub_proc(0b10101011, 0b01000101)
         out = yield dut.out
         assert 0b11101111 == out, f'ERROR: {out} != {0b11101111}'
 
-        # test logical xor
-        yield dut.op.eq(6)
+        # test binary nor
+        yield dut.op.eq(AluOpCodes.bit_nor.value)
+        yield from sub_proc(0b10001011, 0b01000101)
+        out = yield dut.out
+        assert 0b11111111111111111111111100110000 == out, f'ERROR: {bin(out)} != {bin(0b11111111111111111111111100110000)}'
+
+        # test binary xor
+        yield dut.op.eq(AluOpCodes.bit_xor.value)
         yield from sub_proc(0b10001011, 0b01000101)
         out = yield dut.out
         assert 0b11001110 == out, f'ERROR: {out} != {0b11001110}'
 
         # test logical shift left
-        yield dut.op.eq(7)
-        yield from sub_proc(0b10001011, 5) # shift left by 5
+        yield dut.op.eq(AluOpCodes.lleft.value)
+        yield from sub_proc(0b10001011, 25) # shift left by 5
         out = yield dut.out
-        assert 0b1000101100000 == out, f'ERROR: {out} != {0b1000101100000}'
+        assert 0b00010110000000000000000000000000 == out, f'ERROR: {bin(out)} != {bin(0b00010110000000000000000000000000)}'
+        out = yield dut.c_out
+        assert 1 == out, f'ERROR: {out} != {1}'
 
         # test logical shift right
-        yield dut.op.eq(8)
-        yield from sub_proc(0b10001011, 5) # shift right by 5
+        yield dut.op.eq(AluOpCodes.lright.value)
+        yield from sub_proc(0b10001011, 4) # shift right by 5
         out = yield dut.out
-        assert 0b100 == out, f'ERROR: {out} != {0b100}'
+        assert 0b1000 == out, f'ERROR: {bin(out)} != {bin(0b1000)}'
+        out = yield dut.c_out
+        assert 1 == out, f'ERROR: {out} != {1}'
 
         # test aligned shift right
-        yield dut.op.eq(9)
+        yield dut.op.eq(AluOpCodes.aright.value)
         yield from sub_proc(0x80001234, 4) # shift right by 4
         out = yield dut.out
         assert 0xF8000123 == out, f'ERROR: {out} != {0xF8000123}'
+        out = yield dut.c_out
+        assert 0 == out, f'ERROR: {out} != {0}'
 
         # test unsigned overflow
-        yield dut.op.eq(0b0000)
+        yield dut.op.eq(AluOpCodes.add.value)
         yield from sub_proc(0xFFFFFFFF, 1) # add 1 to 0xFFFFFFFF
         out = yield dut.overflow
         assert out == 1, f'ERROR: {out} != {1}'
-        out = yield dut.carry
-        assert out == 1, f'ERROR: {out} != {1}'
-
-        # test signed overflow
-        yield dut.op.eq(0b0010)
-        yield from sub_proc(0x7FFFFFFF, 1) # add 1 to 0x7FFFFFFF
-        out = yield dut.overflow
+        out = yield dut.c_out
         assert out == 1, f'ERROR: {out} != {1}'
-        out = yield dut.carry
-        assert out == 0, f'ERROR: {out} != {0}'
 
         # test unsigned underflow
-        yield dut.op.eq(0b0001)
+        yield dut.op.eq(AluOpCodes.add.value)
         yield from sub_proc(0, -1) # subtract 1 from 0
         out = yield dut.overflow
         assert out == 1, f'ERROR: {out} != {1}'
-        out = yield dut.carry
-        assert out == 1, f'ERROR: {out} != {1}'
-
-        # test signed underflow
-        yield dut.op.eq(0b0010)
-        yield from sub_proc(0x80000000, -1) # sub 1 from 0x80000000 (most negative number in two's complement)
-        assert out == 1, f'ERROR: {out} != {1}'
-        out = yield dut.carry
-        assert out == 1, f'ERROR: {out} != {1}'
+        out = yield dut.c_out
+        assert out == 0, f'ERROR: {out} != {0}'
 
         # test zero
-        yield dut.op.eq(0b0000)
+        yield dut.op.eq(AluOpCodes.add.value)
         yield from sub_proc(0, 0) # add 0 to 0
         out = yield dut.zero
         assert out == 1, f'ERROR: {out} != {1}'
 
         # test zero
-        yield dut.op.eq(0b0000)
+        yield dut.op.eq(AluOpCodes.add.value)
         yield from sub_proc(0, 1) # add 0 to 0
         out = yield dut.zero
         assert out == 0, f'ERROR: {out} != {0}'