Add tcam test, fix tcam

sim/net_core/sim.yaml

@@ -1,2 +1,3 @@
 yaml:
-  - "parser/sim.yaml"
+  - "parser/sim.yaml"
+  - "tcam/sim.yaml"

sim/net_core/tcam/sim.yaml

@@ -0,0 +1,7 @@
+tests:
+  - name: "tcam_sanity"
+    toplevel: "tcam"
+    modules:
+      - "tcam_sanity"
+    sources: "sources.list"
+    waves: True

sim/net_core/tcam/sources.list

@@ -0,0 +1,4 @@
+../../verilator.vlt
+
+../../../src/net_core/sources.list
+../../../src/common/taxi_sources.list

sim/net_core/tcam/tcam_sanity.py

@@ -0,0 +1,65 @@
+import cocotb
+
+import logging
+
+from cocotb.clock import Clock
+from cocotb.triggers import Timer, RisingEdge, FallingEdge
+
+import random
+
+CLK_PERIOD = 20
+
+
+class TB:
+    def __init__(self, dut):
+        self.dut = dut
+
+        self.log = logging.getLogger("cocotb.tb")
+        self.log.setLevel(logging.INFO)
+
+        cocotb.start_soon(Clock(self.dut.i_clk, CLK_PERIOD, unit="ns").start())
+
+
+    async def program_line(self, addr: int, value: int):
+        self.dut.i_program_addr.value = addr
+        self.dut.i_program_data.value = value & (2**32-1)
+        self.dut.i_program_we.value = 1
+        await RisingEdge(self.dut.i_clk)
+        self.dut.i_program_addr.value = 0
+        self.dut.i_program_data.value = 0
+        self.dut.i_program_we.value = 0
+
+    async def send_data(self, value: int):
+        self.dut.i_search_data.value = value & (2**32-1)
+        self.dut.i_search_valid.value = 1
+        await RisingEdge(self.dut.i_clk)
+        self.dut.i_search_data.value = 0
+        self.dut.i_search_valid.value = 0
+
+@cocotb.test
+async def test_sanity(dut):
+    tb = TB(dut)
+
+    for _ in range(4):
+        await RisingEdge(tb.dut.i_clk)
+
+    for i in range(32):
+        await tb.program_line(i, 0xffffffff)
+        await tb.program_line(i+32, 0xffffffff)
+
+    for _ in range(4):
+        await RisingEdge(tb.dut.i_clk)
+    
+    await tb.program_line(0,  0x5432edc0)
+    await tb.program_line(32, 0xabcd1230)
+
+    await tb.program_line(1, ~0xabcd1234)
+    await tb.program_line(33, 0xabcd1234)
+
+    for _ in range(4):
+        await RisingEdge(tb.dut.i_clk)
+
+    await tb.send_data(0xabcd1234)
+    await tb.send_data(0xabcd1235)
+
+    await Timer(1, "us")