Add SBR instruction

src/Emulator/Core.hs

@@ -81,6 +81,7 @@ executeInstruction mutRegisters mutMemory flags pc sp instruction = do
         ROL rd -> rol mutRegisters mutMemory flags sp rd
         ROR rd -> ror mutRegisters mutMemory flags sp rd
         SBC rd rr -> sbc mutRegisters mutMemory flags sp rd rr
+        SBR rd k -> sbr mutRegisters mutMemory flags sp rd k
         SBRC rd b -> sbrc mutRegisters flags sp rd b
         SBRS rd b -> sbrs mutRegisters flags sp rd b
         SEC -> sec flags sp

src/Emulator/Instructions.hs

@@ -109,6 +109,7 @@ data Instruction
     | ROL Register
     | ROR Register
     | SBC Register Register
+    | SBR Register Word8
     | SBRC Register Word8
     | SBRS Register Word8
     | SEC
@@ -917,6 +918,21 @@ sbc registers memory oldFlags sp op1 op2 = do
     }
     return (updatedFlags, 0, sp)
 
+sbr :: MutRegisters s -> MutMemory s -> StatusFlags -> StackPointer -> Register -> Word8 -> ST s (StatusFlags, Int, StackPointer)
+sbr registers memory oldFlags sp op1 immediate = do
+    let rdIndex = fromIntegral op1
+    rd <- getRegister registers rdIndex
+    let k = immediate
+    let result = rd .|. k
+    setRegister registers memory rdIndex result
+    let updatedFlags = oldFlags {
+        overflowFlag = False,
+        negativeFlag = testBit result 7,
+        zeroFlag = result == 0,
+        signFlag = xor (negativeFlag updatedFlags) (overflowFlag updatedFlags)
+    }
+    return (updatedFlags, 0, sp)
+
 sbrc :: MutRegisters s -> StatusFlags -> StackPointer -> Register -> Word8 -> ST s (StatusFlags, Int, StackPointer)
 sbrc registers oldFlags sp op1 immediate = do
     let rdIndex = fromIntegral op1

src/Parser.hs

@@ -559,6 +559,14 @@ pSBRS = do
     pComma
     SBRS rd <$> pDecimal
 
+pSBR :: Parser Instruction
+pSBR = do
+    cistring "SBR" >> space1
+    rd <- pRegister
+    when (rd < 16) (fail "Can't use SBR with registers lower than R16")
+    pComma
+    SBR rd <$> pWord8
+
 pSEC :: Parser Instruction
 pSEC = do
     cistring "SEC" >> (space1 <|> eof)
@@ -726,6 +734,7 @@ instructionParser = do
         pSBC,
         pSBRC,
         pSBRS,
+        pSBR,
         pSEC,
         pSEH,
         pSEI,

src/Repl.hs

@@ -322,10 +322,10 @@ helpText = unlines
   , "  e                           Run until the end of the program"
   , "  f                           Run until the next RET or RETI instruction"
   , "  restart | re                Restart the emulator with the same parameters"
-  , "  registers | r               Print the current values of the register"
+  , "  registers | r               Print the current values of the registers"
   , "  flags                       Print the current values of the status flags"
-  , "  pc | p                      Print the ccurent value of the program counter"
-  , "  m [[<start>] <end>]         Print the memory contents between those addresses"
+  , "  pc | p                      Print the curent value of the program counter"
+  , "  m [[<start>] <end>]         Print the memory contents between two addresses"
   , "  instruction | i             Print the next instruction to be executed"
   , "  help                        Print this message"
   , "  Control-D                   Exit the REPL"

test/MainTests.hs

@@ -255,6 +255,11 @@ main = hspec $ describe "AVR Emulator E2E tests" $ do
       let assemblyFilePath = "test_files/test_bset.asm"
       emulateProgramFromFile assemblyFilePath testBset
 
+    -- test_sbr.asm
+    it "Should correctly emulate test_sbr.asm and match expected state" $ do
+      let assemblyFilePath = "test_files/test_sbr.asm"
+      emulateProgramFromFile assemblyFilePath testSbr
+
 -- Checking emulator state for array_merge.asm
 testArrayMerge :: EmulatorState -> IO ()
 testArrayMerge state = do
@@ -1302,3 +1307,23 @@ testBset state = do
     negativeFlag (flags state) `shouldBe` True
     zeroFlag (flags state) `shouldBe` True
     carryFlag (flags state) `shouldBe` True
+
+-- Checking EmulatorState for the "test_sbr.asm"
+testSbr :: EmulatorState -> IO ()
+testSbr state = do
+    -- Registers
+    let regValue = registers state ! 16
+    regValue `shouldBe` 0xAF
+
+    -- Program counter
+    programCounter state `shouldBe` 2
+
+    -- Status flags
+    interruptFlag (flags state) `shouldBe` False
+    tFlag (flags state) `shouldBe` False
+    halfCarryFlag (flags state) `shouldBe` False
+    signFlag (flags state) `shouldBe` True
+    overflowFlag (flags state) `shouldBe` False
+    negativeFlag (flags state) `shouldBe` True
+    zeroFlag (flags state) `shouldBe` False
+    carryFlag (flags state) `shouldBe` False

test_files/test_sbr.asm

@@ -0,0 +1,2 @@
+    ldi r16, 0xAA         ; r16 = 0xAA
+    sbr r16, 0x0F         ; r16 = 0xAA OR 0x0F = 0xAF