smc1102: added timer

src/devices/cpu/tms1000/smc1102.cpp

@@ -19,10 +19,8 @@ SMC1112 die notes (SMC1102 is assumed to be the same):
 - no output PLA
 
 TODO:
-- each opcode is 4 cycles instead of 6
 - LCD refresh timing is unknown
 - add (micro)instructions PLA if it turns out it can be customized
-- add timer
 - add halt opcode
 
 */
@@ -72,6 +70,11 @@ void smc1102_cpu_device::device_start()
 	m_selin = 0;
 	m_k_line = false;
 
+	m_div = 0;
+	m_timer = 0;
+	m_timeout = false;
+	m_tmset = 0;
+
 	memset(m_stack, 0, sizeof(m_stack));
 	m_sp = 0;
 	m_pb_stack = 0;
@@ -87,6 +90,11 @@ void smc1102_cpu_device::device_start()
 	save_item(NAME(m_selin));
 	save_item(NAME(m_k_line));
 
+	save_item(NAME(m_div));
+	save_item(NAME(m_timer));
+	save_item(NAME(m_timeout));
+	save_item(NAME(m_tmset));
+
 	save_item(NAME(m_stack));
 	save_item(NAME(m_sp));
 	save_item(NAME(m_pb_stack));
@@ -102,6 +110,7 @@ void smc1102_cpu_device::device_reset()
 
 	m_inten = false;
 	m_selin = 0;
+	m_timeout = false;
 
 	// changed/added fixed instructions (mostly handled in op_extra)
 	m_fixed_decode[0x0a] = F_EXTRA;
@@ -186,11 +195,12 @@ void smc1102_cpu_device::read_opcode()
 	}
 
 	// check interrupts (blocked after INTEN)
-	if (m_inten && m_opcode != 0x74)
+	if (m_opcode != 0x74)
 	{
-		bool taken = (m_selin & 2) ? false : m_k_line;
+		const bool taken = (m_selin & 2) ? m_timeout : m_k_line;
+		m_timeout = false;
 
-		if (taken)
+		if (m_inten && taken)
 		{
 			interrupt();
 			return;
@@ -223,6 +233,46 @@ void smc1102_cpu_device::interrupt()
 	m_inten = false;
 }
 
+void smc1102_cpu_device::execute_run()
+{
+	while (m_icount > 0)
+	{
+		m_icount--;
+
+		// decrement timer
+		m_div = (m_div + 1) & 0x1fff;
+		const u16 tmask = (m_selin & 1) ? 0x1ff : 0x1fff;
+		if ((m_div & tmask) == 0)
+		{
+			m_timer = (m_timer - 1) & 0xf;
+			if (m_timer == 0)
+			{
+				m_timer = m_tmset;
+				m_timeout = true;
+			}
+		}
+
+		// 4 cycles per opcode instead of 6
+		switch (m_subcycle)
+		{
+			case 2:
+				execute_one(2);
+				execute_one(3);
+				break;
+
+			case 3:
+				execute_one(4);
+				execute_one(5);
+				break;
+
+			default:
+				execute_one(m_subcycle);
+				break;
+		}
+		m_subcycle = (m_subcycle + 1) & 3;
+	}
+}
+
 
 // opcode deviations
 void smc1102_cpu_device::op_call()
@@ -283,6 +333,7 @@ void smc1102_cpu_device::op_selin()
 void smc1102_cpu_device::op_tmset()
 {
 	// TMSET: transfer A to timer latch
+	m_tmset = m_a;
 }
 
 void smc1102_cpu_device::op_halt()

src/devices/cpu/tms1000/smc1102.h

@@ -62,6 +62,7 @@ protected:
 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
 
 	virtual u32 decode_micro(offs_t offset) override;
+	virtual void execute_run() override;
 
 	virtual void read_opcode() override;
 	void interrupt();
@@ -92,6 +93,11 @@ protected:
 	u8 m_selin;
 	bool m_k_line;
 
+	u16 m_div;
+	u8 m_timer;
+	bool m_timeout;
+	u8 m_tmset;
+
 	// stack
 	u16 m_stack[4];
 	u8 m_sp;

src/devices/cpu/tms1000/tms1k_base.cpp

@@ -598,9 +598,9 @@ void tms1k_base_device::op_tpc()
 //  execute
 //-------------------------------------------------
 
-void tms1k_base_device::execute_one()
+void tms1k_base_device::execute_one(int subcycle)
 {
-	switch (m_subcycle)
+	switch (subcycle)
 	{
 	case 0:
 		// fetch: rom address 1/2
@@ -735,8 +735,6 @@ void tms1k_base_device::execute_one()
 		// execute: br/call 1/2
 		break;
 	}
-
-	m_subcycle = (m_subcycle + 1) % 6;
 }
 
 void tms1k_base_device::execute_run()
@@ -744,6 +742,8 @@ void tms1k_base_device::execute_run()
 	while (m_icount > 0)
 	{
 		m_icount--;
-		execute_one();
+
+		execute_one(m_subcycle);
+		m_subcycle = (m_subcycle + 1) % 6;
 	}
 }

src/devices/cpu/tms1000/tms1k_base.h

@@ -62,7 +62,7 @@ protected:
 	virtual u32 execute_min_cycles() const noexcept override { return 1; }
 	virtual u32 execute_max_cycles() const noexcept override { return 1; }
 	virtual void execute_run() override;
-	virtual void execute_one();
+	virtual void execute_one(int subcycle);
 
 	// device_memory_interface overrides
 	virtual space_config_vector memory_space_config() const override;

src/mame/layout/starwlb.lay

@@ -26,8 +26,8 @@ license:CC0-1.0
 	</element>
 
 	<element name="lamp" defstate="0">
-		<disk state="1"><color red="1.0" green="1.0" blue="1.0" /></disk>
-		<disk state="0"><color red="0.25" green="0.25" blue="0.25" /></disk>
+		<disk state="1"><color red="1.0" green="0.97" blue="0.9" /></disk>
+		<disk state="0"><color red="0.3" green="0.3" blue="0.3" /></disk>
 	</element>
 
 	<element name="hl" defstate="0">