1 files changed, 103 insertions, 0 deletions
diff --git a/src/ucode.py b/src/ucode.py
new file mode 100755
index 0000000..ea5c040
--- /dev/null
+++ b/src/ucode.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+# Generate .bin file with ATK16 CPU microcode
+
+# Addressed by OOOO BUUU
+# where O = opcode, B = branch flag, U = microsequencer value
+
+import sys
+
+if len(sys.argv) != 2:
+  print("usage: ucode.py <outfile.bin>")
+  sys.exit(1)
+
+outfile_path = sys.argv[1]
+
+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
+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
+HALT    = 0b0100_0000_0000_0000
+US_RS   = 0b1000_0000_0000_0000
+
+BRANCH_FLAG_STATES_N = 2
+UCODE_N = 2**3
+CONTROL_WORD_SIZE = 2
+
+def not_branch(bs):
+  return BRANCH_FLAG_STATES_N * [bs]
+
+def branch(false_branch, true_branch):
+  return [false_branch, true_branch]
+
+fetch = [PC_OE|MAR_IE, RAM_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]),
+  # 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]),
+  # JMP 0101 RRRX XXXX XXXX
+  not_branch([*fetch, R1_OE|PC_IE, US_RS, 0, 0, 0, 0]),
+  # BR  0110 XFFR RRXX XXXX
+  branch([*fetch, US_RS, 0, 0, 0, 0, 0],
+         [*fetch, R2_OE|PC_IE, US_RS, 0, 0, 0, 0]),
+  # NOP 0111 XXXX XXXX XXXX
+  nop(),
+  # NOP 1000 XXXX XXXX XXXX
+  nop(),
+  # NOP 1001 XXXX XXXX XXXX
+  nop(),
+  # NOP 1010 XXXX XXXX XXXX
+  nop(),
+  # NOP 1011 XXXX XXXX XXXX
+  nop(),
+  # NOP 1100 XXXX XXXX XXXX
+  nop(),
+  # NOP 1101 XXXX XXXX XXXX
+  nop(),
+  # NOP 1110 XXXX XXXX XXXX
+  nop(),
+  # HLT 1111 XXXX XXXX XXXX
+  not_branch([*fetch, HALT, 0, 0, 0, 0, 0]),
+]
+
+INST_N = len(ucode)
+TOTAL_BYTEARRAY_SIZE = INST_N * BRANCH_FLAG_STATES_N * UCODE_N * CONTROL_WORD_SIZE
+
+res_b = bytearray(TOTAL_BYTEARRAY_SIZE)
+
+for i in range(INST_N):
+  for j in range(BRANCH_FLAG_STATES_N):
+    for k in range(UCODE_N):
+      for l in range(CONTROL_WORD_SIZE):
+        idx = l + \
+            k * CONTROL_WORD_SIZE + \
+            j * CONTROL_WORD_SIZE * UCODE_N + \
+            i * CONTROL_WORD_SIZE * UCODE_N * BRANCH_FLAG_STATES_N
+        cword = ucode[i][j][k]
+        assert len(ucode[i][j]) == 8
+        cbyte = (cword >> (8 * (CONTROL_WORD_SIZE - l - 1))) & 0xff
+        print(f"inst: {i:>04b}, idx: {idx:>04x}, cbyte: {cbyte:>08b}")
+        res_b[idx] = cbyte
+
+with open(outfile_path, "wb") as f:
+  f.write(res_b)