add an idealized NoC

+ Purely virtual, doesn't exist, but would be 'theoretically' ideal.

1 files changed, 34 insertions, 0 deletions

diff --git a/include/gran/ideal_noc.h b/include/gran/ideal_noc.h
new file mode 100644
index 0000000..638454a
--- /dev/null
+++ b/include/gran/ideal_noc.h
@@ -0,0 +1,34 @@
+#ifndef GRAN_IDEAL_NOC_H
+#define GRAN_IDEAL_NOC_H
+
+/**
+ * Essentially, this is the behaviour of a NoC that everyone wants, but nobody
+ * knows how to get. All-to all, single cycle, with oldest-first arbitration.
+ *
+ * I don't think it's been proven to be physically/mathematically
+ * impossible to build such a system (with reasonable performance/area costs),
+ * but at least there's no known way with existing mainstream technologies.
+ * There are some interesting future research areas, like adding wireless elements
+ * to the NoC, optical interconnects, superconducting routers and pulse computing,
+ * but nothing definite as far as I'm aware. Still, might be fun to compare how
+ * close to an idealized situation we can get, and maybe just daydream.
+ */
+
+#include <stdint.h>
+#include <gran/component.h>
+
+struct component *create_ideal_noc(uint32_t elems, size_t latency);
+stat ideal_noc_connect(struct component *noc, struct component *component, uint32_t elem);
+
+static inline void addr_ideal_noc(uint64_t addr, uint32_t *elem, uint32_t *off)
+{
+	if (off) *off = addr & 0xffffffff;
+	if (elem) *elem = (addr >> 32) & 0xffffffff;
+}
+
+static inline uint64_t ideal_noc_addr(uint32_t elem, uint32_t off)
+{
+	return ((uint64_t)elem << 32) | off;
+}
+
+#endif /* GRAN_IDEAL_NOC_H */