From 0c63c46e31642d0102542a745af6b445a9d22b3b Mon Sep 17 00:00:00 2001
From: Alejandro Soto <alejandro@34project.org>
Date: Tue, 13 Dec 2022 21:43:25 -0600
Subject: Implement interrupt controller

---
 tb/interrupt.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 tb/interrupt.cpp

(limited to 'tb/interrupt.cpp')

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;
+	}
+}
-- 
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