From 80f66556795c80603cf7b33140adc27e01e37155 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 27 Apr 2020 12:49:49 +0100
Subject: [PATCH] add LDST PortInterface class

---
 src/soc/experiment/l0_cache.py | 65 ++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 src/soc/experiment/l0_cache.py

diff --git a/src/soc/experiment/l0_cache.py b/src/soc/experiment/l0_cache.py
new file mode 100644
index 00000000..774491a5
--- /dev/null
+++ b/src/soc/experiment/l0_cache.py
@@ -0,0 +1,65 @@
+from nmigen.compat.sim import run_simulation
+from nmigen.cli import verilog, rtlil
+from nmigen import Module, Signal, Mux, Elaboratable, Array
+from nmutil.iocontrol import RecordObject
+
+from nmutil.latch import SRLatch, latchregister
+from soc.decoder.power_decoder2 import Data
+from soc.decoder.power_enums import InternalOp
+
+from soc.experiment.compldst import CompLDSTOpSubset
+from soc.decoder.power_decode2 import Data
+
+
+class PortInterface(RecordObject):
+
+    def __init__(self, name=None):
+
+        RecordObject.__init__(self, name=name)
+
+        # distinguish op type (ld/st)
+        self.is_ld_i = Signal(reset_less=True)
+        self.is_st_i = Signal(reset_less=True)
+        self.op = CompLDSTOpSubset() # hm insn_type ld/st duplicates here
+
+        # common signals
+        self.busy_o = Signal(reset_less=True)     # do not use if busy
+        self.go_die_i = Signal(reset_less=True)   # back to reset
+        self.addr = Data(48, "addr_i")            # addr/addr-ok
+        self.addr_ok_o = Signal(reset_less=True)  # addr is valid (TLB, L1 etc.)
+        self.addr_exc_o = Signal(reset_less=True) # TODO, "type" of exception
+
+        # LD/ST
+        self.ld = Data(64, "ld_data_o") # ok to be set by L0 Cache/Buf
+        self.st = Data(64, "st_data_i") # ok to be set by CompUnit
+
+
+class L0CacheBuffer(Elaboratable):
+    """L0 Cache / Buffer
+
+    Note that the final version will have *two* interfaces per LDSTCompUnit,
+    to cover mis-aligned requests.
+    """
+
+    def __init__(self, n_units):
+        self.n_units = n_units
+        ul = []
+        for i in range(n_units):
+            ul.append(PortInterface("ldst_port%d" % i))
+        self.ports = Array(ul)
+
+
+def test_l0_cache():
+    from alu_hier import ALU
+
+    alu = ALU(16)
+    dut = ComputationUnitNoDelay(16, alu)
+    vl = rtlil.convert(dut, ports=dut.ports())
+    with open("test_compalu.il", "w") as f:
+        f.write(vl)
+
+    run_simulation(dut, scoreboard_sim(dut), vcd_name='test_compalu.vcd')
+
+
+if __name__ == '__main__':
+    test_l0_cache()
-- 
2.30.2