add skeleton implementation of experiment/formal/proof_icache.py to

so I can solicit help

diff --git a/src/soc/experiment/formal/proof_icache.py b/src/soc/experiment/formal/proof_icache.py
new file mode 100644 (file)
index 0000000..1e9a714
--- /dev/null
+++ b/src/soc/experiment/formal/proof_icache.py
@@ -0,0 +1,61 @@
+from nmigen import (Cat, Const, Elaboratable, Module, Signal, signed)
+from nmigen.asserts import (Assert, AnyConst, AnySeq, Assume)
+from nmutil.formaltest import FHDLTestCase
+from nmutil.stageapi import StageChain
+from nmigen.cli import rtlil
+
+import unittest
+
+from soc.experiment.icache import ICache
+
+from nmigen_soc.wishbone.sram import SRAM
+from nmigen import Memory
+
+class Driver(Elaboratable):
+    def elaborate(self, platform):
+        m     = Module()
+        comb  = m.d.comb
+        sync  = m.d.sync
+
+        mem_init = [(i*2) | ((i*2+1) << 32) for i in range(512)]
+        memory   = Memory(width=64, depth=512, init=mem_init)
+        sram     = SRAM(memory=memory, granularity=8)
+
+        m.submodules.dut  = dut = ICache()
+        m.submodules.sram = sram
+
+        m.d.comb += sram.bus.cyc.eq(dut.wb_out.cyc)
+        m.d.comb += sram.bus.stb.eq(dut.wb_out.stb)
+        m.d.comb += sram.bus.we.eq(dut.wb_out.we)
+        m.d.comb += sram.bus.sel.eq(dut.wb_out.sel)
+        m.d.comb += sram.bus.adr.eq(dut.wb_out.adr)
+        m.d.comb += sram.bus.dat_w.eq(dut.wb_out.dat)
+
+        m.d.comb += dut.wb_in.ack.eq(sram.bus.ack)
+        m.d.comb += dut.wb_in.dat.eq(sram.bus.dat_r)
+
+        i_out     = dut.i_in
+        i_in      = dut.i_out
+        m_out     = dut.m_in
+        stall_in  = dut.stall_in
+        stall_out = dut.stall_out
+        flush_in  = dut.flush_in
+        inval_in  = dut.inval_in
+        wb_in     = dut.wb_in
+        wb_out    = dut.wb_out
+        log_out   = dut.log_out
+
+
+class ICacheTestCase(FHDLTestCase):
+    def test_formal(self):
+        self.assertFormal(Driver(), mode="bmc", depth=10)
+        self.assertFormal(Driver(), mode="cover", depth=10)
+
+    def test_ilang(self):
+        vl = rtlil.convert(Driver(), ports=[])
+        with open("icache_formal.il", "w") as f:
+            f.write(vl)
+
+
+if __name__ == '__main__':
+    unittest.main()