Move from logisim to digital

4 files changed, 61 insertions, 39 deletions

diff --git a/src/assembler.py b/src/assembler.py
index 9e2d92f..5802983 100755
--- a/src/assembler.py
+++ b/src/assembler.py
@@ -45,7 +45,7 @@ def parse(line: str) -> list[str]:
 
 def eval_expr(expr: str) -> int:
   expr = eval_symbol(expr)
-  return eval(expr, labels) # eval as Python expr
+  return eval(expr, labels.copy()) # eval as Python expr
 
 def eval_symbol(c: str):
   if c in labels:
@@ -85,7 +85,7 @@ labels: dict[str, int] = {}
 address = 0
 
 for (lineNo, line) in enumerate(src_lines):
-  line = line.strip()
+  line = line.split(";")[0].strip()
   if line == "": continue
   keyword, *args = line.lower().split()
   match keyword:
@@ -98,8 +98,6 @@ for (lineNo, line) in enumerate(src_lines):
 
   address += 1
 
-print("labels:", labels)
-
 # 2nd pass
 
 address = 0
@@ -122,33 +120,50 @@ for (lineNo, line) in enumerate(src_lines):
 
     # Instructions
     case "alu":
+      # S (alu op)
+      # L (lhs)
+      # R (rhs)
+      # T (target)
       word = (0b0000 << 12) + \
-             (eval_expr(args[0]) << 9) + \
-             (eval_expr(args[1]) << 6) + \
-             (eval_expr(args[2]) << 3) + \
+             (eval_expr(args[0]) << 3) + \
+             (eval_expr(args[1]) << 9) + \
+             (eval_expr(args[2]) << 6) + \
              (eval_expr(args[3]) << 0)
     case "als":
+      # S (alu op)
+      # L (lhs)
+      # R (rhs)
+      # T (target)
       word = (0b0001 << 12) + \
-             (eval_expr(args[0]) << 9) + \
-             (eval_expr(args[1]) << 6) + \
-             (eval_expr(args[2]) << 3) + \
+             (eval_expr(args[0]) << 3) + \
+             (eval_expr(args[1]) << 9) + \
+             (eval_expr(args[2]) << 6) + \
              (eval_expr(args[3]) << 0)
     case "ldr":
+      # R (address)
+      # T (target)
       word = (0b0010 << 12) + \
              (eval_expr(args[0]) << 9) + \
-             (eval_expr(args[1]) << 6)
+             (eval_expr(args[1]) << 0)
     case "str":
+      # R (address)
+      # T (value to store)
       word = (0b0011 << 12) + \
              (eval_expr(args[0]) << 9) + \
              (eval_expr(args[1]) << 6)
     case "ldi":
+      # T (target)
+      # I (immediate)
       word = (0b0100 << 12) + \
-             (eval_expr(args[0]) << 9) + \
-             (eval_expr(args[1]) << 0)
+             (eval_expr(args[0]) << 0) + \
+             (eval_expr(args[1]) << 3)
     case "jmp":
+      # R (reg holding address)
       word = (0b0101 << 12) + \
              (eval_expr(args[0]) << 9)
     case "br":
+      # F (flag selector)
+      # R (reg holding address)
       word = (0b0110 << 12) + \
              (eval_expr(args[0]) << 9) + \
              (eval_expr(args[1]) << 6)
@@ -160,20 +175,20 @@ for (lineNo, line) in enumerate(src_lines):
       word = (0b0000                   << 12) + \
              (eval_expr(args[0])       << 9) + \
              (eval_expr(args[1])       << 6) + \
-             (eval_expr(args[2])       << 3) + \
-             (eval_expr("al_a_plus_b") << 0)
+             (eval_expr("al_a_plus_b") << 3) + \
+             (eval_expr(args[2])       << 0)
     case "sub":
       word = (0b0000                    << 12) + \
              (eval_expr(args[0])        << 9) + \
              (eval_expr(args[1])        << 6) + \
-             (eval_expr(args[2])        << 3) + \
-             (eval_expr("al_a_minus_b") << 0)
+             (eval_expr("al_a_minus_b") << 3) + \
+             (eval_expr(args[2])        << 0)
     case "mov":
       word = (0b0000                   << 12) + \
              (eval_expr("rz")          << 9) + \
              (eval_expr(args[0])       << 6) + \
-             (eval_expr(args[1])       << 3) + \
-             (eval_expr("al_a_plus_b") << 0)
+             (eval_expr("al_a_plus_b") << 3) + \
+             (eval_expr(args[1])       << 0)
 
     # Default case: evaluate as is (e.g. data word)
     case _:
@@ -185,6 +200,10 @@ for (lineNo, line) in enumerate(src_lines):
   if len(result) < 2 * address + 1:
     result.extend((2 * address + 1 - len(result)) * nop)
 
+  for (label, label_addr) in labels.items():
+    if address == label_addr:
+      print(f"{label}:")
+
   print(f"{address:>08x}  0x{word:>04x}  {line}")
   result[2 * address + 0] = ((word >> 8) & 0xff)
   result[2 * address + 1] = ((word >> 0) & 0xff)
diff --git a/src/test.atk16 b/src/test.atk16
index 399bd7e..364480b 100644
--- a/src/test.atk16
+++ b/src/test.atk16
@@ -10,7 +10,7 @@
 
 @label program
   ldi RA 10         ; RA := 10
-  ldi RB 20         ; RB := 10
+  ldi RB 20         ; RB := 20
   add RA RB RC      ; RC := RA + RB
   ldi RD ram_offset ; store address of ram_offset in RD
   ldr RD RD         ; dereference ram_offset address
diff --git a/src/test_sum.atk16 b/src/test_sum.atk16
new file mode 100644
index 0000000..3f69a55
--- /dev/null
+++ b/src/test_sum.atk16
@@ -0,0 +1,3 @@
+  ldi RA 10         ; RA := 10
+  ldi RB 20         ; RB := 20
+  add RA RB RC      ; RC := RA + RB
diff --git a/src/ucode.py b/src/ucode.py
index ea5c040..9d7c55c 100755
--- a/src/ucode.py
+++ b/src/ucode.py
@@ -16,16 +16,16 @@ PC_CO   = 0b0000_0000_0000_0001
 PC_IE   = 0b0000_0000_0000_0010
 PC_OE   = 0b0000_0000_0000_0100
 MAR_IE  = 0b0000_0000_0000_1000
-RAM_IE  = 0b0000_0000_0001_0000
-RAM_OE  = 0b0000_0000_0010_0000
-R1_IE   = 0b0000_0000_0100_0000
+MEM_IE  = 0b0000_0000_0001_0000
+MEM_OE  = 0b0000_0000_0010_0000
+RW_IE   = 0b0000_0000_0100_0000
 R1_OE   = 0b0000_0000_1000_0000
-R2_IE   = 0b0000_0001_0000_0000
-R2_OE   = 0b0000_0010_0000_0000
-IR_IE   = 0b0000_0100_0000_0000
-L9_OE   = 0b0000_1000_0000_0000
-L12_OE  = 0b0001_0000_0000_0000
-ALU_OE  = 0b0010_0000_0000_0000
+R2_OE   = 0b0000_0001_0000_0000
+IR_IE   = 0b0000_0010_0000_0000
+L9_OE   = 0b0000_0100_0000_0000
+unused1 = 0b0000_1000_0000_0000
+ALU_OE  = 0b0001_0000_0000_0000
+FR_IE   = 0b0010_0000_0000_0000
 HALT    = 0b0100_0000_0000_0000
 US_RS   = 0b1000_0000_0000_0000
 
@@ -39,22 +39,22 @@ def not_branch(bs):
 def branch(false_branch, true_branch):
   return [false_branch, true_branch]
 
-fetch = [PC_OE|MAR_IE, RAM_OE|IR_IE|PC_CO]
+fetch = [PC_OE|MAR_IE, MEM_OE|IR_IE|PC_CO]
 
 def nop():
   return not_branch([*fetch, US_RS, 0, 0, 0, 0, 0])
 
 ucode = [
-  # ALU 0000 LLLR RRTT TSSS
-  not_branch([*fetch, ALU_OE, US_RS, 0, 0, 0, 0]),
-  # ALS 0001 LLLR RRTT TSSS
-  not_branch([*fetch, ALU_OE, US_RS, 0, 0, 0, 0]),
-  # LDR 0010 RRRT TTXX XXXX
-  not_branch([*fetch, R1_OE|MAR_IE, RAM_OE|R2_IE, US_RS, 0, 0, 0]),
+  # ALU 0000 LLLR RRSS STTT
+  not_branch([*fetch, ALU_OE|FR_IE|RW_IE, US_RS, 0, 0, 0, 0]),
+  # ALS 0001 LLLR RRSS STTT
+  not_branch([*fetch, ALU_OE|FR_IE|RW_IE, US_RS, 0, 0, 0, 0]),
+  # LDR 0010 RRRX XXXX XTTT
+  not_branch([*fetch, R1_OE|MAR_IE, MEM_OE|RW_IE, US_RS, 0, 0, 0]),
   # STR 0011 RRRT TTXX XXXX
-  not_branch([*fetch, R1_OE|MAR_IE, R2_OE|RAM_IE, US_RS, 0, 0, 0]),
-  # LDI 0100 RRRI IIII IIII
-  not_branch([*fetch, L9_OE|R1_IE, US_RS, 0, 0, 0, 0]),
+  not_branch([*fetch, R1_OE|MAR_IE, R2_OE|MEM_IE, US_RS, 0, 0, 0]),
+  # LDI 0100 IIII IIII ITTT
+  not_branch([*fetch, H9_OE|RW_IE, US_RS, 0, 0, 0, 0]),
   # JMP 0101 RRRX XXXX XXXX
   not_branch([*fetch, R1_OE|PC_IE, US_RS, 0, 0, 0, 0]),
   # BR  0110 XFFR RRXX XXXX