Implement interrupt controller

1 files changed, 63 insertions, 0 deletions

diff --git a/tb/interrupt.cpp b/tb/interrupt.cpp
new file mode 100644
index 0000000..4164bb7
--- /dev/null
+++ b/tb/interrupt.cpp
@@ -0,0 +1,63 @@
+#include <cstdint>
+
+#include "avalon.hpp"
+
+namespace taller::avalon
+{
+	interrupt_controller::interrupt_controller(std::uint32_t base) noexcept
+	: slave(base, 8, 4)
+	{}
+
+	bool interrupt_controller::read(std::uint32_t addr, std::uint32_t &data) noexcept
+	{
+		switch(addr)
+		{
+			case 0:
+				data = status();
+				break;
+
+			case 1:
+				data = mask;
+				break;
+		}
+
+		return true;
+	}
+
+	bool interrupt_controller::write(std::uint32_t addr, std::uint32_t data, unsigned byte_enable) noexcept
+	{
+		switch(addr)
+		{
+			case 0:
+				break;
+
+			case 1:
+				mask = data;
+				break;
+		}
+
+		return true;
+	}
+
+	bool interrupt_controller::irq() noexcept
+	{
+		return status() != 0;
+	}
+
+	std::uint32_t interrupt_controller::status() noexcept
+	{
+		std::uint32_t lines = 0;
+
+		if(irqs.timer)
+		{
+			lines |= irqs.timer->irq() << 0;
+		}
+
+		if(irqs.jtaguart)
+		{
+			lines |= irqs.jtaguart->irq() << 1;
+		}
+
+		return lines & mask;
+	}
+}