Z80: indicate NMI and INT cycles when single stepping

Change-Id: Iafef4059bd136dd9f3aebf2b03ab5ac186e035a6

firmware/AtomBusMon.c

@@ -1333,6 +1333,7 @@ void doCmdContinue(char *params) {
 }
 
 void initialize() {
+  PDC_DDR = 0;
   CTRL_DDR = 255;
   STATUS_DDR = MUXSEL_MASK;
   MUX_DDR = 0;

firmware/AtomBusMon.h

@@ -46,6 +46,7 @@ void doCmdHelp(char *params);
 void doCmdIO(char *params);
 void doCmdList(char *params);
 void doCmdMem(char *params);
+void doCmdNext(char *params);
 void doCmdReadIO(char *params);
 void doCmdReadMem(char *params);
 void doCmdRegs(char *params);

firmware/dis.h

@@ -1,6 +1,11 @@
 #ifndef __DIS_DEFINES__
 #define __DIS_DEFINES__
 
+// The processor dependent config/status port
+#define PDC_PORT         PORTA
+#define PDC_DDR          DDRA
+#define PDC_DIN          PINA
+
 unsigned int disassemble(unsigned int addr);
 
 #endif

firmware/disz80.c

@@ -862,7 +862,13 @@ void disassem (unsigned int *ip) {
 
 unsigned int disassemble(unsigned int addr) {
   log0("%04X : ", addr);
-  disassem(&addr);
+  if (PDC_DIN & 0x80) {
+    log0("**NMI**");
+  } else if (PDC_DIN & 0x40) {
+    log0("**INT**");
+  } else {
+    disassem(&addr);
+  }
   log0("\n");
   return addr;
 }

src/BusMonCore.vhd

@@ -56,6 +56,9 @@ entity BusMonCore is
         -- unused in pure bus monitor mode
         Regs             : in    std_logic_vector(255 downto 0);
 
+        -- CPI Specific data
+        PdcData          : in    std_logic_vector(7 downto 0) := x"00";
+
         -- CPU Memory Read/Write
         -- unused in pure bus monitor mode
         RdMemOut         : out std_logic;
@@ -182,15 +185,7 @@ begin
         clk16M               => clock_avr,
         nrst                 => nrst_avr,
 
-        portain(0)           => '0',
-        portain(1)           => '0',
-        portain(2)           => '0',
-        portain(3)           => '0',
-        portain(4)           => '0',
-        portain(5)           => '0',
-        portain(6)           => '0',
-        portain(7)           => '0',
-
+        portain              => PdcData,
         portaout             => open,
 
         -- Command Port

src/T80/T80.vhd

@@ -117,6 +117,7 @@ entity T80 is
 		MC         : out std_logic_vector(2 downto 0);
 		TS         : out std_logic_vector(2 downto 0);
 		IntCycle_n : out std_logic;
+		NMICycle_n : out std_logic;
 		IntE       : out std_logic;
 		Stop       : out std_logic;
 		out0       : in  std_logic := '0';  -- 0 => OUT(C),0, 1 => OUT(C),255
@@ -1170,6 +1171,7 @@ begin
 	HALT_n <= not Halt_FF;
 	BUSAK_n <= not BusAck;
 	IntCycle_n <= not IntCycle;
+	NMICycle_n <= not NMICycle;
 	IntE <= IntE_FF1;
 	IORQ <= IORQ_i;
 	Stop <= I_DJNZ;

src/T80/T80_Pack.vhd

@@ -103,6 +103,7 @@ package T80_Pack is
 		MC                      : out std_logic_vector(2 downto 0);
 		TS                      : out std_logic_vector(2 downto 0);
 		IntCycle_n      : out std_logic;
+		NMICycle_n      : out std_logic;
 		IntE            : out std_logic;
 		Stop            : out std_logic;
 		REG             : out std_logic_vector(211 downto 0); -- IFF2, IFF1, IM, IY, HL', DE', BC', IX, HL, DE, BC, PC, SP, R, I, F', A', F, A

src/T80/T80a.vhd

@@ -72,8 +72,9 @@ entity T80a is
     );
     port(
         -- Additions
-        TS              : out std_logic_vector(2 downto 0);
-        Regs            : out std_logic_vector(255 downto 0);
+        TS          : out std_logic_vector(2 downto 0);
+        Regs        : out std_logic_vector(255 downto 0);
+        PdcData     : out std_logic_vector(7 downto 0);
         -- Original Signals
         RESET_n     : in std_logic;
         CLK_n       : in std_logic;
@@ -101,6 +102,7 @@ architecture rtl of T80a is
 
     signal Reset_s      : std_logic;
     signal IntCycle_n   : std_logic;
+    signal NMICycle_n   : std_logic;
     signal IORQ         : std_logic;
     signal NoRead       : std_logic;
     signal Write        : std_logic;
@@ -175,6 +177,7 @@ begin
             MC => MCycle,
             TS => TState,
             IntCycle_n => IntCycle_n,
+            NMICycle_n => NMICycle_n,
             REG => Regs(211 downto 0),
             DIRSet => '0',
             DIR => (others => '0')
@@ -297,4 +300,7 @@ begin
     end process;
 
     TS <= TState;
+
+    PdcData <= (not NMICycle_n) & (not IntCycle_n) & "000000";
+
 end;

src/Z80CpuMon.vhd

@@ -121,6 +121,7 @@ type state_type is (idle, nop_t1, nop_t2, nop_t3, nop_t4, rd_t1, rd_wa, rd_t2, r
     signal skipNextOpcode : std_logic;
 
     signal Regs           : std_logic_vector(255 downto 0);
+    signal PdcData        : std_logic_vector(7 downto 0);
     signal io_not_mem     : std_logic;
     signal io_rd          : std_logic;
     signal io_wr          : std_logic;
@@ -249,6 +250,7 @@ begin
         tdin         => tdin,
         tcclk        => tcclk,
         Regs         => Regs,
+        PdcData      => PdcData,
         RdMemOut     => memory_rd,
         WrMemOut     => memory_wr,
         RdIOOut      => io_rd,
@@ -270,6 +272,7 @@ begin
         inst_t80: entity work.T80a port map (
             TS      => TState,
             Regs    => Regs,
+            PdcData => PdcData,
             RESET_n => RESET_n_int,
             CLK_n   => cpu_clk,
             CEN     => cpu_clken,