fix typo introduced during refactor

src/manta/logic_analyzer/trigger_block.py

@@ -18,8 +18,8 @@ class LogicAnalyzerTriggerBlock(Elaboratable):
         self.r = IOCore({"outputs": outputs}, base_addr, interface)
 
         # Bus Input/Output
-        self.bus_i = Signal(InternalBus())
-        self.bus_o = Signal(InternalBus())
+        self.bus_i = self.r.bus_i
+        self.bus_o = self.r.bus_o
 
         # Global trigger. High if any probe is triggered.
         self.trig = Signal(1)

src/manta/utils.py

@@ -4,6 +4,9 @@ from math import ceil
 import os
 
 class InternalBus(data.StructLayout):
+    """Describes the layout of Manta's internal bus, such that signals of
+    the appropriate dimension can be instantiated with Signal(InternalBus()).
+    """
     def __init__(self):
         super().__init__({
             "addr": 16,