hmcs40 WIP

src/emu/cpu/hmcs40/hmcs40.c

@@ -65,7 +65,8 @@ ADDRESS_MAP_END
 
 static ADDRESS_MAP_START(data_160x4, AS_DATA, 8, hmcs40_cpu_device)
 	AM_RANGE(0x00, 0x7f) AM_RAM
-	AM_RANGE(0x80, 0x9f) AM_RAM AM_MIRROR(0x70)
+	AM_RANGE(0x80, 0x8f) AM_RAM AM_MIRROR(0x30)
+	AM_RANGE(0xc0, 0xcf) AM_RAM AM_MIRROR(0x30)
 ADDRESS_MAP_END
 
 
@@ -95,6 +96,10 @@ void hmcs40_cpu_device::state_string_export(const device_state_entry &entry, ast
 			);
 			break;
 
+		case STATE_GENPC:
+			string.printf("%03X", m_pc << 1);
+			break;
+
 		default: break;
 	}
 }
@@ -123,6 +128,7 @@ void hmcs40_cpu_device::device_start()
 	m_data = &space(AS_DATA);
 	m_prgmask = (1 << m_prgwidth) - 1;
 	m_datamask = (1 << m_datawidth) - 1;
+	m_xmask = (1 << (m_datawidth - 4)) - 1;
 
 	m_read_d.resolve_safe(0);
 	m_write_d.resolve_safe();
@@ -130,6 +136,7 @@ void hmcs40_cpu_device::device_start()
 	// zerofill
 	memset(m_stack, 0, sizeof(m_stack));
 	m_op = 0;
+	m_arg = 0;
 	m_pc = 0;
 	m_a = 0;
 	m_b = 0;
@@ -143,6 +150,7 @@ void hmcs40_cpu_device::device_start()
 	// register for savestates
 	save_item(NAME(m_stack));
 	save_item(NAME(m_op));
+	save_item(NAME(m_arg));
 	save_item(NAME(m_pc));
 	save_item(NAME(m_a));
 	save_item(NAME(m_b));
@@ -162,7 +170,7 @@ void hmcs40_cpu_device::device_start()
 	state_add(HMCS40_Y,   "Y",   m_y).formatstr("%01X");
 	state_add(HMCS40_SPY, "SPY", m_spy).formatstr("%01X");
 
-	state_add(STATE_GENPC, "curpc", m_pc).formatstr("%04X").noshow();
+	state_add(STATE_GENPC, "curpc", m_pc).formatstr("%03X").noshow();
 	state_add(STATE_GENFLAGS, "GENFLAGS", m_s).formatstr("%2s").noshow();
 
 	m_icountptr = &m_icount;
@@ -176,7 +184,7 @@ void hmcs40_cpu_device::device_start()
 
 void hmcs40_cpu_device::device_reset()
 {
-	m_pc = 0;
+	m_pc = 0xffff & m_prgmask;
 	m_op = 0;
 }
 
@@ -186,14 +194,41 @@ void hmcs40_cpu_device::device_reset()
 //  execute
 //-------------------------------------------------
 
+inline void hmcs40_cpu_device::increment_pc()
+{
+	// PC lower bits is a LFSR identical to TI TMS1000
+	UINT8 mask = 0x3f;
+	UINT8 low = m_pc & mask;
+	int fb = (low << 1 & 0x20) == (low & 0x20);
+
+	if (low == (mask >> 1))
+		fb = 1;
+	else if (low == mask)
+		fb = 0;
+
+	m_pc = (m_pc & ~mask) | ((m_pc << 1 | fb) & mask);
+}
+
+inline void hmcs40_cpu_device::fetch_arg()
+{
+	// P is the only 2-byte opcode
+	if (m_op == 0x3ff)
+	{
+		m_icount--;
+		m_arg = m_program->read_word(m_pc << 1);
+		increment_pc();
+	}
+}
+
 void hmcs40_cpu_device::execute_run()
 {
 	while (m_icount > 0)
 	{
 		m_icount--;
 		
-		debugger_instruction_hook(this, m_pc);
+		debugger_instruction_hook(this, m_pc << 1);
-		m_op = m_program->read_byte(m_pc);
+		m_op = m_program->read_word(m_pc << 1);
-		m_pc = (m_pc + 1) & m_prgmask;
+		increment_pc();
+		fetch_arg();
 	}
 }

src/emu/cpu/hmcs40/hmcs40.h

@@ -68,9 +68,11 @@ protected:
 	int m_datawidth;
 	int m_prgmask;
 	int m_datamask;
+	int m_xmask;
 	int m_stack_levels; // number of callstack levels
 	UINT16 m_stack[4];  // max 4
 	UINT16 m_op;
+	UINT16 m_arg;
 	int m_icount;
 	
 	UINT16 m_pc;        // Program Counter
@@ -87,6 +89,15 @@ protected:
 	devcb_read16 m_read_d;
 	devcb_write16 m_write_d;
 
+	// misc internal helpers
+	void increment_pc();
+	void fetch_arg();
+
+	UINT8 ram_r();
+	void ram_w(UINT8 data);
+	void pop_stack();
+	void push_stack();
+
 	// opcode handlers
 	void op_lab();
 	void op_lba();
@@ -104,7 +115,7 @@ protected:
 	void op_ayy();
 	void op_syy();
 	void op_xspx();
-	void op_sxpy();
+	void op_xspy();
 	void op_xspxy();
 
 	void op_lam();

src/emu/cpu/hmcs40/hmcs40op.inc

@@ -2,6 +2,32 @@
 
 // internal helpers
 
+inline UINT8 hmcs40_cpu_device::ram_r()
+{
+	UINT8 address = (m_x << 4 | m_y) & m_datamask;
+	return m_data->read_byte(address) & 0xf;
+}
+
+inline void hmcs40_cpu_device::ram_w(UINT8 data)
+{
+	UINT8 address = (m_x << 4 | m_y) & m_datamask;
+	m_data->write_byte(address, data & 0xf);
+}
+
+void hmcs40_cpu_device::pop_stack()
+{
+	m_pc = m_stack[0] & m_prgmask;
+	for (int i = 0; i < m_stack_levels-1; i++)
+		m_stack[i] = m_stack[i+1];
+}
+
+void hmcs40_cpu_device::push_stack()
+{
+	for (int i = m_stack_levels-1; i >= 1; i--)
+		m_stack[i] = m_stack[i-1];
+	m_stack[0] = m_pc;
+}
+
 void hmcs40_cpu_device::op_illegal()
 {
 	logerror("%s unknown opcode $%03X at $%04X\n", tag(), m_op, m_pc);
@@ -16,37 +42,45 @@ void hmcs40_cpu_device::op_illegal()
 void hmcs40_cpu_device::op_lab()
 {
 	// LAB: Load A from B
-	op_illegal();
+	m_a = m_b;
 }
 
 void hmcs40_cpu_device::op_lba()
 {
 	// LBA: Load B from A
-	op_illegal();
+	m_b = m_a;
 }
 
 void hmcs40_cpu_device::op_lay()
 {
 	// LAY: Load A from Y
-	op_illegal();
+	m_a = m_y;
 }
 
 void hmcs40_cpu_device::op_laspx()
 {
 	// LASPX: Load A from SPX
-	op_illegal();
+	m_a = m_spx;
 }
 
 void hmcs40_cpu_device::op_laspy()
 {
 	// LASPY: Load A from SPY
-	op_illegal();
+	m_a = m_spy;
 }
 
 void hmcs40_cpu_device::op_xamr()
 {
 	// XAMR m: Exchange A and MR(m)
-	op_illegal();
+	
+	// determine MR(Memory Register) location
+	UINT8 y = m_op & 0xf;
+	UINT8 x = (y > 3) ? 0xf : (y + 12);
+	UINT8 address = (x << 4 | y) & m_datamask;
+	
+	UINT8 old_a = m_a;
+	m_a = m_data->read_byte(address) & 0xf;
+	m_data->write_byte(address, old_a & 0xf);
 }
 
 
@@ -55,67 +89,78 @@ void hmcs40_cpu_device::op_xamr()
 void hmcs40_cpu_device::op_lxa()
 {
 	// LXA: Load X from A
-	op_illegal();
+	m_x = m_a;
 }
 
 void hmcs40_cpu_device::op_lya()
 {
 	// LYA: Load Y from A
-	op_illegal();
+	m_y = m_a;
 }
 
 void hmcs40_cpu_device::op_lxi()
 {
 	// LXI i: Load X from Immediate
-	op_illegal();
+	m_x = m_op & 0xf;
 }
 
 void hmcs40_cpu_device::op_lyi()
 {
 	// LYI i: Load Y from Immediate
-	op_illegal();
+	m_y = m_op & 0xf;
 }
 
 void hmcs40_cpu_device::op_iy()
 {
 	// IY: Increment Y
-	op_illegal();
+	m_y = (m_y + 1) & 0xf;
+	m_s = (m_y != 0);
 }
 
 void hmcs40_cpu_device::op_dy()
 {
 	// DY: Decrement Y
-	op_illegal();
+	m_y = (m_y - 1) & 0xf;
+	m_s = (m_y != 0xf);
 }
 
 void hmcs40_cpu_device::op_ayy()
 {
 	// AYY: Add A to Y
-	op_illegal();
+	m_y += m_a;
+	m_s = m_y >> 4 & 1;
+	m_y &= 0xf;
 }
 
 void hmcs40_cpu_device::op_syy()
 {
 	// SYY: Subtract A from Y
-	op_illegal();
+	m_y -= m_a;
+	m_s = ~m_y >> 4 & 1;
+	m_y &= 0xf;
 }
 
 void hmcs40_cpu_device::op_xspx()
 {
 	// XSPX: Exchange X and SPX
-	op_illegal();
+	UINT8 old_x = m_x;
+	m_x = m_spx;
+	m_spx = old_x;
 }
 
-void hmcs40_cpu_device::op_sxpy()
+void hmcs40_cpu_device::op_xspy()
 {
-	// SXPY: Exchange Y and SPY
+	// XSPY: Exchange Y and SPY
-	op_illegal();
+	UINT8 old_y = m_y;
+	m_y = m_spy;
+	m_spy = old_y;
 }
 
 void hmcs40_cpu_device::op_xspxy()
 {
 	// XSPXY: Exchange X and SPX, Y and SPY
-	op_illegal();
+	op_xspx();
+	op_xspy();
 }
 
 
@@ -124,37 +169,49 @@ void hmcs40_cpu_device::op_xspxy()
 void hmcs40_cpu_device::op_lam()
 {
 	// LAM (XY): Load A from Memory
-	op_illegal();
+	m_a = ram_r();
+	op_xspxy();
 }
 
 void hmcs40_cpu_device::op_lbm()
 {
 	// LBM (XY): Load B from Memory
-	op_illegal();
+	m_b = ram_r();
+	op_xspxy();
 }
 
 void hmcs40_cpu_device::op_xma()
 {
 	// XMA (XY): Exchange Memory and A
-	op_illegal();
+	UINT8 old_a = m_a;
+	m_a = ram_r();
+	ram_w(old_a);
+	op_xspxy();
 }
 
 void hmcs40_cpu_device::op_xmb()
 {
 	// XMB (XY): Exchange Memory and B
-	op_illegal();
+	UINT8 old_b = m_b;
+	m_b = ram_r();
+	ram_w(old_b);
+	op_xspxy();
 }
 
 void hmcs40_cpu_device::op_lmaiy()
 {
 	// LMAIY (X): Load Memory from A, Increment Y
-	op_illegal();
+	ram_w(m_a);
+	op_iy();
+	op_xspx();
 }
 
 void hmcs40_cpu_device::op_lmady()
 {
 	// LMADY (X): Load Memory from A, Decrement Y
-	op_illegal();
+	ram_w(m_a);
+	op_dy();
+	op_xspx();
 }
 
 
@@ -163,19 +220,20 @@ void hmcs40_cpu_device::op_lmady()
 void hmcs40_cpu_device::op_lmiiy()
 {
 	// LMIIY i: Load Memory from Immediate, Increment Y
-	op_illegal();
+	ram_w(m_op & 0xf);
+	op_iy();
 }
 
 void hmcs40_cpu_device::op_lai()
 {
 	// LAI i: Load A from Immediate
-	op_illegal();
+	m_a = m_op & 0xf;
 }
 
 void hmcs40_cpu_device::op_lbi()
 {
 	// LBI i: Load B from Immediate
-	op_illegal();
+	m_b = m_op & 0xf;
 }