Trigger selection

cores/signal/signal_scope/tool/capture_plot.py

@@ -53,6 +53,12 @@ def parse_args() -> argparse.Namespace:
         default=None,
         help="Optional trigger threshold (16-bit, signal_a rising crossing). If omitted, triggering is disabled.",
     )
+    parser.add_argument(
+        "--trigger-channel",
+        choices=["a", "b", "c", "d"],
+        default="a",
+        help="Trigger source channel when triggering is enabled",
+    )
     parser.add_argument(
         "--unsigned",
         action="store_true",
@@ -81,15 +87,20 @@ def parse_args() -> argparse.Namespace:
 def capture_once(bridge, args: argparse.Namespace) -> list[tuple[int, int, int, int]]:
     samples = []
     frame_count = args.depth
+    trigger_channel_map = {"a": 0, "b": 1, "c": 2, "d": 3}
+    trigger_channel = trigger_channel_map[args.trigger_channel]
     if args.trigger_value is None:
         print("[signal_scope] Arming scope with trigger disabled...")
         bridge.write32(REG_CONTROL, 0x1)  # bit0: arm pulse, bit1: trigger enable=0
     else:
         trig_val = args.trigger_value & 0xFFFF
-        print(f"[signal_scope] Config trigger: trig_val=0x{trig_val:04x}, source=signal_a rising")
+        print(
+            f"[signal_scope] Config trigger: trig_val=0x{trig_val:04x}, "
+            f"source=signal_{args.trigger_channel} rising"
+        )
         bridge.write32(REG_TRIG_VAL, trig_val)
         print("[signal_scope] Arming scope with trigger enabled...")
-        bridge.write32(REG_CONTROL, 0x3)  # bit0: arm pulse, bit1: trigger enable
+        bridge.write32(REG_CONTROL, 0x3 | (trigger_channel << 2))  # bit0: arm, bit1: trig_en, bits[3:2]: channel
 
         # Wait until the new arm command is active, then wait for its trigger event.
         while (bridge.read32(REG_STATUS) & 0x4) == 0: