mcs51: Add read/write slave address registers to 80c51

Author: galibert

src/devices/cpu/mcs51/i80c51.cpp

@@ -13,6 +13,43 @@ DEFINE_DEVICE_TYPE(P80C552, p80c552_device, "p80c552", "Philips P80C552")
 DEFINE_DEVICE_TYPE(P87C552, p87c552_device, "p87c552", "Philips P87C552")
 DEFINE_DEVICE_TYPE(P80C562, p80c562_device, "p80c562", "Philips P80C562")
 
+void i80c51_device::device_start()
+{
+	mcs51_cpu_device::device_start();
+	m_slave_address = 0;
+	m_slave_mask = 0;
+
+	save_item(NAME(m_slave_address));
+	save_item(NAME(m_slave_mask));
+}
+
+void i80c51_device::sfr_map(address_map &map)
+{
+	mcs51_cpu_device::sfr_map(map);
+	map(0xa9, 0xa9).rw(FUNC(i80c51_device::slave_address_r), FUNC(i80c51_device::slave_address_w));
+	map(0xb9, 0xb9).rw(FUNC(i80c51_device::slave_mask_r), FUNC(i80c51_device::slave_mask_w));
+}
+
+void i80c51_device::slave_address_w(u8 data)
+{
+	m_slave_address = data;
+}
+
+u8 i80c51_device::slave_address_r()
+{
+	return m_slave_address;
+}
+
+void i80c51_device::slave_mask_w(u8 data)
+{
+	m_slave_mask = data;
+}
+
+u8 i80c51_device::slave_mask_r()
+{
+	return m_slave_mask;
+}
+
 bool i80c51_device::manage_idle_on_interrupt(u8 ints)
 {
 	/* any interrupt terminates idle mode */

src/devices/cpu/mcs51/i80c51.h

@@ -24,10 +24,19 @@ class i80c51_device : public mcs51_cpu_device
 	i80c51_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
 
 protected:
+	u8 m_slave_address, m_slave_mask;
+
 	i80c51_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock, int program_width, int io_width);
 
+	virtual void sfr_map(address_map &map) override ATTR_COLD;
 	virtual bool manage_idle_on_interrupt(u8 ints) override;
 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
+	virtual void device_start() override ATTR_COLD;
+
+	void slave_address_w(u8 data);
+	u8 slave_address_r();
+	void slave_mask_w(u8 data);
+	u8 slave_mask_r();
 };
 
 class i80c31_device : public i80c51_device