Added breakpoint functionality

Change-Id: I82b1162249a1bfed2d340361b205340dfbb70d86

firmware/AtomBusMon.c

@@ -7,10 +7,20 @@
 
 #define CTRL_PORT PORTB
 #define CTRL_DDR  DDRB
+#define CTRL_DIN  PINB
+
+// Outputs
 #define STEP_MASK 0x01
 #define SINGLE_MASK 0x02
 #define RESET_MASK 0x04
-#define CTRL_MASK (SINGLE_MASK | STEP_MASK | RESET_MASK)
+#define BRKPT_ENABLE_MASK 0x08
+#define BRKPT_CLOCK_MASK 0x10
+#define BRKPT_DATA_MASK  0x20
+// Inputs
+#define BRKPT_INTERRUPTED_MASK  0x40
+#define BRKPT_ACTIVE_MASK  0x80
+
+#define CTRL_MASK (SINGLE_MASK | STEP_MASK | RESET_MASK | BRKPT_ENABLE_MASK | BRKPT_CLOCK_MASK | BRKPT_DATA_MASK)
 
 #define AL_PORT PORTD
 #define AL_DIN  PIND
@@ -22,7 +32,7 @@
 #define AH_MASK 0x00
 #define AH_DDR  DDRE
 
-#define VERSION "0.10"
+#define VERSION "0.11"
 
 #define NUMCMDS 10
 #define MAXBKPTS 4
@@ -43,14 +53,14 @@ unsigned int breakpoints[MAXBKPTS] = {
 char *cmdStrings[NUMCMDS] = {
   "help",
   "reset",
-  "break",
+  "interrupt",
-  "continue",
   "address",
   "step",
   "trace",
   "blist",
-  "bset",
+  "break",
-  "bclear"
+  "bclear",
+  "continue",
 };
 
 #define Delay_us(__us) \
@@ -105,34 +115,33 @@ void setSingle(int i) {
   single = i;
   if (single) {
     CTRL_PORT |= SINGLE_MASK;
-    log0("Single stepping enabled\n");
   } else {
     CTRL_PORT &= ~SINGLE_MASK;
-    log0("Single stepping disabled\n");
   }
+  Delay_us(10);
 }
 
 void setTrace(long i) {
   trace = i;
   if (trace) {
-    log0("Tracing every %ld instructions\n", trace);
+    log0("Tracing every %ld instructions while single stepping\n", trace);
   } else {
     log0("Tracing disabled\n");
   }
 }
 
+void version() {
+  log0("Atom Bus Monitor version %s\n", VERSION);
+  log0("Compiled at %s on %s\n",__TIME__,__DATE__);
+}
 
 /*******************************************
  * Commands
  *******************************************/
 
-void notImplemented() {
-  log0("Not implemented\n");
-}
-
 void doCmdHelp(char *params) {
   int i;
-  log0("Atom Bus Monitor version %s\n", VERSION);
+  version();
   log0("Commands:\n");
   for (i = 0; i < NUMCMDS; i++) {
     log0("    %s\n", cmdStrings[i]);
@@ -168,10 +177,11 @@ void doCmdStep(char *params) {
   for (i = 1; i <= instructions; i++) {
     // Step the 6502
     CTRL_PORT &= ~STEP_MASK;
-    Delay_us(1);
+    Delay_us(2);
     CTRL_PORT |= STEP_MASK;
-    Delay_us(1);
+    Delay_us(2);
     if (i == instructions || (trace && (--j == 0))) {
+      Delay_us(10);
       doCmdAddr();
       j = trace;
     }
@@ -185,15 +195,11 @@ void doCmdReset(char *params) {
   CTRL_PORT &= ~RESET_MASK;
 }
 
-void doCmdBreak(char *params) {
+void doCmdInterrupt(char *params) {
-  setSingle(true);
+  setSingle(1);
   doCmdAddr();
 }
 
-void doCmdContinue(char *params) {
-  setSingle(false);
-}
-
 
 void doCmdTrace(char *params) {
   long i;
@@ -212,7 +218,7 @@ void doCmdBList(char *params) {
   }
 }
 
-void doCmdBSet(char *params) {
+void doCmdBreak(char *params) {
   int i;
   unsigned int addr;
   sscanf(params, "%x", &addr);
@@ -221,6 +227,14 @@ void doCmdBSet(char *params) {
     doCmdBList(NULL);
     return;
   }
+  for (i = 0; i < numbkpts; i++) {
+    if (breakpoints[i] == addr) {
+      log0("Breakpoint already set at %04X\n", addr);
+      doCmdBList(NULL);
+      return;
+    }
+  }
+
   numbkpts++;
   for (i = numbkpts - 2; i >= -1; i--) {
     if (i == -1 || breakpoints[i] < addr) {
@@ -228,10 +242,6 @@ void doCmdBSet(char *params) {
       breakpoints[i + 1] = addr;
       doCmdBList(NULL);
       return;
-    } else if (breakpoints[i] == addr) {
-      log0("Breakpoint already set at %04X\n", addr);
-      doCmdBList(NULL);
-      return;
     } else {
       breakpoints[i + 1] = breakpoints[i];
     }
@@ -240,7 +250,7 @@ void doCmdBSet(char *params) {
 
 void doCmdBClear(char *params) {
   int i;
-  int n;
+  int n = 0;
   sscanf(params, "%d", &n);
   if (n >= numbkpts) {
     log0("Breakpoint %d not set\n", n);
@@ -254,30 +264,89 @@ void doCmdBClear(char *params) {
   doCmdBList(NULL);
 }
 
+void shiftBreakpointRegister(unsigned int addr) {
+  int i;
+  for (i = 0; i < 16; i++) {
+    CTRL_PORT &= ~BRKPT_CLOCK_MASK;
+    if (addr & 1) {
+      CTRL_PORT |= BRKPT_DATA_MASK;
+    } else {
+      CTRL_PORT &= ~BRKPT_DATA_MASK;
+    }
+    Delay_us(10);
+    CTRL_PORT |= BRKPT_CLOCK_MASK;
+    Delay_us(10);
+    addr >>= 1;
+  }
+}
+
+void doCmdContinue(char *params) {
+  int i;
+  int status;
+  doCmdBList(NULL);
+
+  // Disable breakpoints to allow loading
+  CTRL_PORT &= ~BRKPT_ENABLE_MASK;
+
+  // Load breakpoints into comparators
+  for (i = 0; i < MAXBKPTS; i++) {
+    shiftBreakpointRegister(i < numbkpts ? breakpoints[i] : 0);
+  }
+
+  // Enable breakpoints
+  CTRL_PORT |= BRKPT_ENABLE_MASK;
+
+  // Disable single stepping
+  setSingle(0);
+
+  // Wait for breakpoint to become active
+  log0("6502 free running...\n");
+  do {
+    status = CTRL_DIN;
+  } while (!(status & BRKPT_ACTIVE_MASK) && !(status && BRKPT_INTERRUPTED_MASK));
+
+  // Output cause
+  if (status & BRKPT_ACTIVE_MASK) {
+    log0("Breakpoint hit at ");
+  } else {
+    log0("Interrupted at ");
+  }
+  doCmdAddr();
+
+  // Enable single stepping
+  setSingle(1);
+
+  // Disable breakpoints
+  CTRL_PORT &= ~BRKPT_ENABLE_MASK;
+}
+
+
 void initialize() {
   CTRL_DDR = CTRL_MASK;
   AL_DDR  = AL_MASK;
   AH_DDR  = AH_MASK;
-  CTRL_PORT &= ~STEP_MASK;
+  CTRL_PORT &= 0;
   Serial_Init(57600,57600);
   lcd_init();
   lcd_puts("Addr: xxxx");
-  log0("Atom Bus Monitor\n");
+  version();
-  setSingle(false);
+  setSingle(1);
-  setTrace(0);
+  setTrace(1);
+  log0("6502 paused...\n");
+  doCmdAddr();
 }
 
 void (*cmdFuncs[NUMCMDS])(char *params) = {
   doCmdHelp,
   doCmdReset,
-  doCmdBreak,
+  doCmdInterrupt,
-  doCmdContinue,
   doCmdAddr,
   doCmdStep,
   doCmdTrace,
   doCmdBList,
-  doCmdBSet,
+  doCmdBreak,
-  doCmdBClear
+  doCmdBClear,
+  doCmdContinue
 };
 
 

firmware/status.c

@@ -185,11 +185,9 @@ void Serial_Init(const uint32_t BaudRate0,
 	cls(0);
 	cls(1);
 	
-	log0("stdio initialised\n");
+	// log0("stdio initialised\n");
-	log0("compiled at %s on %s\n",__TIME__,__DATE__);
+	// log0("SerialPort0\n");
-	
+	// log1("SerialPort1\n");
-	log0("SerialPort0\n");
-	log1("SerialPort1\n");
 }
 
 #ifdef USE_HEXDUMP

src/AtomBusMon.vhd

@@ -77,7 +77,21 @@ architecture behavioral of AtomBusMon is
     signal step   : std_logic;
     signal step1  : std_logic;
     signal step2  : std_logic;
+    
+    signal brkpt_enable  : std_logic;
+    signal brkpt_clock   : std_logic;
+    signal brkpt_clock1  : std_logic;
+    signal brkpt_clock2  : std_logic;
+    signal brkpt_data    : std_logic;
+    signal brkpt_active  : std_logic;
+    signal brkpt_active1 : std_logic;
 
+    signal brkpt_0   : std_logic_vector(15 downto 0);
+    signal brkpt_1   : std_logic_vector(15 downto 0);
+    signal brkpt_2   : std_logic_vector(15 downto 0);
+    signal brkpt_3   : std_logic_vector(15 downto 0);
+    signal brkpt_reg : std_logic_vector(63 downto 0);
+    
 begin
 
     inst_dcm5 : entity work.DCM0 port map(
@@ -125,11 +139,23 @@ begin
         portaout(6)          => lcd_db_out(6),
         portaout(7)          => lcd_db_out(7),
 
-        portbin              => (others => '0'),
+        portbin(0)           => '0',
+        portbin(1)           => '0',
+        portbin(2)           => '0',
+        portbin(3)           => '0',
+        portbin(4)           => '0',
+        portbin(5)           => '0',
+        portbin(6)           => sw1,
+        portbin(7)           => brkpt_active1,
         portbout(0)          => step,
         portbout(1)          => single,
         portbout(2)          => reset,
-        portbout(7 downto 3) => open,
+        portbout(3)          => brkpt_enable,
+        portbout(4)          => brkpt_clock,
+        portbout(5)          => brkpt_data,
+        portbout(6)          => open,
+        portbout(7)          => open,
+        
         
         portdin              => addr_inst(7 downto 0),
         portdout             => open,
@@ -149,9 +175,9 @@ begin
     lcd_db    <= lcd_db_out when lcd_rw_int = '0' else (others => 'Z');
     lcd_db_in <= lcd_db;
 
-    led3 <= dy_counter(24); -- red
+    led3 <= '0';               -- red
-    led6 <= dy_counter(24); -- red
+    led6 <= '0';               -- red
-    led8 <= not sw1;        -- green
+    led8 <= not brkpt_active;  -- green
 
     nrst_avr <= nsw2;
     
@@ -160,26 +186,46 @@ begin
     dy_data(1) <= hex & "0000" & Addr(7 downto 4);
     dy_data(2) <= hex & "0000" & "00" & (not nsw2) & sw1;
   
+    brkpt_0 <= brkpt_reg(15 downto 0);
+    brkpt_1 <= brkpt_reg(31 downto 16);
+    brkpt_2 <= brkpt_reg(47 downto 32);
+    brkpt_3 <= brkpt_reg(63 downto 48);
+
+
+    brkpt_active <= '1' when brkpt_enable = '1' and Sync = '1' and
+        ((Addr = brkpt_0) or (Addr = brkpt_1) or (Addr = brkpt_2) or (Addr = brkpt_3))
+        else '0';
+        
     -- 6502 Control
     syncProcess: process (Phi2)
     begin
         if rising_edge(Phi2) then
-            step1 <= step;
+            -- Address monitoring
-            step2 <= step1;
-            if ((single = '0') or (step2 = '0' and step1 = '1')) then
-                Rdy <= '1';
-            else
-                Rdy <= not Sync;
-            end if;
             addr_sync <= Addr;          
             if (Sync = '1') then
                 addr_inst <= Addr;
             end if;
+            -- Reset
             if (reset = '1') then
                 nRST <= '0';
             else
                 nRST <= 'Z';
             end if;
+            -- Breakpoints
+            brkpt_clock1 <= brkpt_clock;
+            brkpt_clock2 <= brkpt_clock1;
+            if (brkpt_enable = '0' and brkpt_clock2 = '0' and brkpt_clock1 = '1') then
+                brkpt_reg <= brkpt_data & brkpt_reg(63 downto 1);
+            end if;
+            brkpt_active1 <= brkpt_active;
+            -- Single Stepping
+            step1 <= step;
+            step2 <= step1;
+            if ((single = '0') or (step2 = '0' and step1 = '1')) then
+                Rdy <= (not brkpt_active);
+            else
+                Rdy <= (not Sync);
+            end if;
         end if;
     end process;