diff --git a/capture/capture_aes.py b/capture/capture_aes.py
index 2f9b06ed..1f2dad2a 100755
--- a/capture/capture_aes.py
+++ b/capture/capture_aes.py
@@ -25,6 +25,7 @@
 import util.helpers as helpers
 from target.communication.sca_aes_commands import OTAES
 from target.communication.sca_prng_commands import OTPRNG
+from target.communication.sca_trigger_commands import OTTRIGGER
 from target.targets import Target, TargetConfig
 from util import check_version
 from util import data_generator as dg
@@ -149,18 +150,17 @@ def setup(cfg: dict, project: Path):
     return target, scope, project
 
 
-def configure_cipher(cfg, target, capture_cfg) -> OTAES:
-    """ Configure the AES cipher.
-
-    Establish communication with the AES cipher and configure the seed.
+def establish_communication(target, capture_cfg: CaptureConfig):
+    """ Establish communication with the target device.
 
     Args:
-        cfg: The project config.
         target: The OT target.
         capture_cfg: The capture config.
 
     Returns:
-        The communication interface to the AES cipher.
+        ot_aes: The communication interface to the AES SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+        ot_trig: The communication interface to the SCA trigger.
     """
     # Create communication interface to OT AES.
     ot_aes = OTAES(target=target, protocol=capture_cfg.protocol)
@@ -168,6 +168,23 @@ def configure_cipher(cfg, target, capture_cfg) -> OTAES:
     # Create communication interface to OT PRNG.
     ot_prng = OTPRNG(target=target, protocol=capture_cfg.protocol)
 
+    # Create communication interface to SCA trigger.
+    ot_trig = OTTRIGGER(target=target, protocol=capture_cfg.protocol)
+
+    return ot_aes, ot_prng, ot_trig
+
+
+def configure_cipher(cfg, capture_cfg, ot_aes, ot_prng):
+    """ Configure the AES cipher.
+
+    Establish communication with the AES cipher and configure the seed.
+
+    Args:
+        cfg: The project config.
+        capture_cfg: The capture config.
+        ot_aes: The communication interface to the AES SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+    """
     # Configure PRNGs.
     # Seed the software LFSR used for initial key masking and additionally
     # turning off the masking when '0'.
@@ -180,8 +197,6 @@ def configure_cipher(cfg, target, capture_cfg) -> OTAES:
         # Seed the target's PRNG.
         ot_prng.seed_prng(cfg["test"]["batch_prng_seed"].to_bytes(4, "little"))
 
-    return ot_aes
-
 
 def generate_ref_crypto(sample_fixed, mode, key, plaintext):
     """ Generate cipher material for the encryption.
@@ -413,8 +428,18 @@ def main(argv=None):
                                 port = cfg["target"].get("port"))
     logger.info(f"Setting up capture {capture_cfg.capture_mode} batch={capture_cfg.batch_mode}...")
 
+    # Open communication with target.
+    ot_aes, ot_prng, ot_trig = establish_communication(target, capture_cfg)
+
     # Configure cipher.
-    ot_aes = configure_cipher(cfg, target, capture_cfg)
+    configure_cipher(cfg, capture_cfg, ot_aes, ot_prng)
+
+    # Configure trigger source.
+    # 0 for HW, 1 for SW.
+    trigger_source = 1
+    if "hw" in cfg["target"].get("trigger"):
+        trigger_source = 0
+    ot_trig.select_trigger(trigger_source)
 
     # Capture traces.
     capture(scope, ot_aes, capture_cfg, project, target)
diff --git a/capture/capture_kmac.py b/capture/capture_kmac.py
index da158894..8c923a77 100755
--- a/capture/capture_kmac.py
+++ b/capture/capture_kmac.py
@@ -29,6 +29,7 @@
 import util.helpers as helpers
 from target.communication.sca_kmac_commands import OTKMAC
 from target.communication.sca_prng_commands import OTPRNG
+from target.communication.sca_trigger_commands import OTTRIGGER
 from target.targets import Target, TargetConfig
 from util import check_version
 from util import data_generator as dg
@@ -153,22 +154,41 @@ def setup(cfg: dict, project: Path):
     return target, scope, project
 
 
-def configure_cipher(cfg, target, capture_cfg) -> OTKMAC:
-    """ Configure the KMAC cipher.
-
-    Establish communication with the KMAC cipher and configure the seed.
+def establish_communication(target, capture_cfg: CaptureConfig):
+    """ Establish communication with the target device.
 
     Args:
-        cfg: The project config.
         target: The OT target.
         capture_cfg: The capture config.
 
     Returns:
-        The communication interface to the KMAC cipher.
+        ot_kmac: The communication interface to the KMAC SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+        ot_trig: The communication interface to the SCA trigger.
     """
     # Create communication interface to OT KMAC.
     ot_kmac = OTKMAC(target=target, protocol=capture_cfg.protocol)
 
+    # Create communication interface to OT PRNG.
+    ot_prng = OTPRNG(target=target, protocol=capture_cfg.protocol)
+
+    # Create communication interface to SCA trigger.
+    ot_trig = OTTRIGGER(target=target, protocol=capture_cfg.protocol)
+
+    return ot_kmac, ot_prng, ot_trig
+
+
+def configure_cipher(cfg, capture_cfg, ot_kmac, ot_prng):
+    """ Configure the KMAC cipher.
+
+    Establish communication with the KMAC cipher and configure the seed.
+
+    Args:
+        cfg: The project config.
+        capture_cfg: The capture config.
+        ot_kmac: The communication interface to the KMAC SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+    """
     # Check if we want to run KMAC SCA for FPGA or discrete. On the FPGA, we
     # can use functionality helping us to capture cleaner traces.
     fpga_mode_bit = 0
@@ -177,9 +197,6 @@ def configure_cipher(cfg, target, capture_cfg) -> OTKMAC:
     # Initialize KMAC on the target.
     ot_kmac.init(fpga_mode_bit)
 
-    # Create communication interface to OT PRNG.
-    ot_prng = OTPRNG(target=target, protocol=capture_cfg.protocol)
-
     # Configure PRNGs.
     # Seed the software LFSR used for initial key masking.
     ot_kmac.write_lfsr_seed(cfg["test"]["lfsr_seed"].to_bytes(4, "little"))
@@ -192,8 +209,6 @@ def configure_cipher(cfg, target, capture_cfg) -> OTKMAC:
         # Seed the target's PRNG.
         ot_prng.seed_prng(cfg["test"]["batch_prng_seed"].to_bytes(4, "little"))
 
-    return ot_kmac
-
 
 def generate_ref_crypto(sample_fixed, mode, batch, key, key_fixed, plaintext,
                         plaintext_fixed, key_length):
@@ -455,8 +470,18 @@ def main(argv=None):
                                 port = cfg["target"].get("port"))
     logger.info(f"Setting up capture {capture_cfg.capture_mode} batch={capture_cfg.batch_mode}...")
 
+    # Open communication with target.
+    ot_kmac, ot_prng, ot_trig = establish_communication(target, capture_cfg)
+
     # Configure cipher.
-    ot_kmac = configure_cipher(cfg, target, capture_cfg)
+    configure_cipher(cfg, capture_cfg, ot_kmac, ot_prng)
+
+    # Configure trigger source.
+    # 0 for HW, 1 for SW.
+    trigger_source = 1
+    if "hw" in cfg["target"].get("trigger"):
+        trigger_source = 0
+    ot_trig.select_trigger(trigger_source)
 
     # Capture traces.
     capture(scope, ot_kmac, capture_cfg, project, target)
diff --git a/capture/capture_otbn.py b/capture/capture_otbn.py
index 06f76b68..82c7e35d 100755
--- a/capture/capture_otbn.py
+++ b/capture/capture_otbn.py
@@ -22,6 +22,7 @@
 
 import util.helpers as helpers
 from target.communication.sca_otbn_commands import OTOTBNVERT
+from target.communication.sca_trigger_commands import OTTRIGGER
 from target.targets import Target, TargetConfig
 from util import check_version
 from util import data_generator as dg
@@ -178,8 +179,28 @@ def setup(cfg: dict, project: Path):
     return target, scope, project
 
 
-def configure_cipher(cfg: dict, target,
-                     capture_cfg: CaptureConfig) -> OTOTBNVERT:
+def establish_communication(target, capture_cfg: CaptureConfig):
+    """ Establish communication with the target device.
+
+    Args:
+        target: The OT target.
+        curve_cfg: The capture config
+
+    Returns:
+        ot_otbn_vert: The communication interface to the OTBN app.
+        ot_trig: The communication interface to the SCA trigger.
+    """
+    # Create communication interface to OTBN.
+    ot_otbn_vert = OTOTBNVERT(target=target, protocol=capture_cfg.protocol)
+
+    # Create communication interface to SCA trigger.
+    ot_trig = OTTRIGGER(target=target, protocol=capture_cfg.protocol)
+
+    return ot_otbn_vert, ot_trig
+
+
+def configure_cipher(cfg: dict, target, capture_cfg: CaptureConfig,
+                     ot_otbn_vert) -> OTOTBNVERT:
     """ Configure the OTBN app.
 
     Establish communication with the OTBN keygen app and configure the seed.
@@ -189,14 +210,11 @@ def configure_cipher(cfg: dict, target,
         target: The OT target.
         curve_cfg: The curve config.
         capture_cfg: The configuration of the capture.
+        ot_otbn_vert: The communication interface to the OTBN app.
 
     Returns:
-        ot_otbn_vert: The communication interface to the OTBN app.
         curve_cfg: The curve configuration values.
     """
-    # Create communication interface to OTBN.
-    ot_otbn_vert = OTOTBNVERT(target=target, protocol=capture_cfg.protocol)
-
     # Seed host's PRNG.
     random.seed(cfg["test"]["batch_prng_seed"])
 
@@ -286,7 +304,7 @@ def configure_cipher(cfg: dict, target,
             capture_cfg.expected_fixed_output = pow(k_fixed_int, -1,
                                                     curve_cfg.curve_order_n)
 
-    return ot_otbn_vert, curve_cfg
+    return curve_cfg
 
 
 def generate_ref_crypto_keygen(cfg: dict, sample_fixed, curve_cfg: CurveConfig,
@@ -717,8 +735,18 @@ def main(argv=None):
         f"Setting up capture {capture_cfg.capture_mode} batch={capture_cfg.batch_mode}..."
     )
 
+    # Open communication with target.
+    ot_otbn_vert, ot_trig = establish_communication(target, capture_cfg)
+
     # Configure cipher.
-    ot_otbn_vert, curve_cfg = configure_cipher(cfg, target, capture_cfg)
+    curve_cfg = configure_cipher(cfg, target, capture_cfg, ot_otbn_vert)
+
+    # Configure trigger source.
+    # 0 for HW, 1 for SW.
+    trigger_source = 1
+    if "hw" in cfg["target"].get("trigger"):
+        trigger_source = 0
+    ot_trig.select_trigger(trigger_source)
 
     # Capture traces.
     if mode == "keygen":
diff --git a/capture/capture_sha3.py b/capture/capture_sha3.py
index 4fd5878b..541ee658 100755
--- a/capture/capture_sha3.py
+++ b/capture/capture_sha3.py
@@ -28,6 +28,7 @@
 import util.helpers as helpers
 from target.communication.sca_prng_commands import OTPRNG
 from target.communication.sca_sha3_commands import OTSHA3
+from target.communication.sca_trigger_commands import OTTRIGGER
 from target.targets import Target, TargetConfig
 from util import check_version
 from util import data_generator as dg
@@ -138,25 +139,41 @@ def setup(cfg: dict, project: Path):
     return target, scope, project
 
 
-def configure_cipher(cfg, target, capture_cfg) -> OTSHA3:
-    """ Configure the SHA3 cipher.
-
-    Establish communication with the SHA3 cipher and configure the seed and mask.
+def establish_communication(target, capture_cfg: CaptureConfig):
+    """ Establish communication with the target device.
 
     Args:
-        cfg: The project config.
         target: The OT target.
         capture_cfg: The capture config.
 
     Returns:
-        The communication interface to the SHA3 cipher.
+        ot_sha3: The communication interface to the SHA3 SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+        ot_trig: The communication interface to the SCA trigger.
     """
     # Create communication interface to OT SHA3.
     ot_sha3 = OTSHA3(target=target, protocol=capture_cfg.protocol)
 
+    # Create communication interface to SCA trigger.
+    ot_trig = OTTRIGGER(target=target, protocol=capture_cfg.protocol)
+
     # Create communication interface to OT PRNG.
     ot_prng = OTPRNG(target=target, protocol=capture_cfg.protocol)
 
+    return ot_sha3, ot_prng, ot_trig
+
+
+def configure_cipher(cfg, capture_cfg, ot_sha3, ot_prng):
+    """ Configure the SHA3 cipher.
+
+    Establish communication with the SHA3 cipher and configure the seed and mask.
+
+    Args:
+        cfg: The project config.
+        capture_cfg: The capture config.
+        ot_sha3: The communication interface to the SHA3 SCA application.
+        ot_prng: The communication interface to the PRNG SCA application.
+    """
     # Check if we want to run KMAC SCA for FPGA or discrete. On the FPGA, we
     # can use functionality helping us to capture cleaner traces.
     fpga_mode_bit = 0
@@ -183,8 +200,6 @@ def configure_cipher(cfg, target, capture_cfg) -> OTSHA3:
         # Seed the target's PRNG.
         ot_prng.seed_prng(cfg["test"]["batch_prng_seed"].to_bytes(4, "little"))
 
-    return ot_sha3
-
 
 def generate_ref_crypto(sample_fixed, mode, batch, plaintext,
                         plaintext_fixed, text_len_bytes):
@@ -427,8 +442,18 @@ def main(argv=None):
                                 port = cfg["target"].get("port"))
     logger.info(f"Setting up capture {capture_cfg.capture_mode} batch={capture_cfg.batch_mode}...")
 
+    # Open communication with target.
+    ot_sha3, ot_prng, ot_trig = establish_communication(target, capture_cfg)
+
     # Configure cipher.
-    ot_sha3 = configure_cipher(cfg, target, capture_cfg)
+    configure_cipher(cfg, capture_cfg, ot_sha3, ot_prng)
+
+    # Configure trigger source.
+    # 0 for HW, 1 for SW.
+    trigger_source = 1
+    if "hw" in cfg["target"].get("trigger"):
+        trigger_source = 0
+    ot_trig.select_trigger(trigger_source)
 
     # Capture traces.
     capture(scope, ot_sha3, capture_cfg, project, target)
diff --git a/capture/configs/aes_sca_chip.yaml b/capture/configs/aes_sca_chip.yaml
index f5ff21ab..0c9f6519 100644
--- a/capture/configs/aes_sca_chip.yaml
+++ b/capture/configs/aes_sca_chip.yaml
@@ -7,6 +7,10 @@ target:
   output_len_bytes: 16
   protocol: "ujson"
   port: "/dev/ttyUSB1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "sw"
 waverunner:
   waverunner_ip: 100.107.71.10
   num_segments: 20
diff --git a/capture/configs/aes_sca_cw305.yaml b/capture/configs/aes_sca_cw305.yaml
index a504e0b6..2af5b9eb 100644
--- a/capture/configs/aes_sca_cw305.yaml
+++ b/capture/configs/aes_sca_cw305.yaml
@@ -9,6 +9,10 @@ target:
   baudrate: 115200
   output_len_bytes: 16
   protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 80
diff --git a/capture/configs/aes_sca_cw310.yaml b/capture/configs/aes_sca_cw310.yaml
index 51af021d..23ca947b 100644
--- a/capture/configs/aes_sca_cw310.yaml
+++ b/capture/configs/aes_sca_cw310.yaml
@@ -12,6 +12,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/capture/configs/kmac_sca_cw310.yaml b/capture/configs/kmac_sca_cw310.yaml
index a5be6bcf..e1b0d1a1 100644
--- a/capture/configs/kmac_sca_cw310.yaml
+++ b/capture/configs/kmac_sca_cw310.yaml
@@ -12,6 +12,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/capture/configs/otbn_vertical_keygen_sca_cw310.yaml b/capture/configs/otbn_vertical_keygen_sca_cw310.yaml
index f80dbd1e..85dbe96e 100644
--- a/capture/configs/otbn_vertical_keygen_sca_cw310.yaml
+++ b/capture/configs/otbn_vertical_keygen_sca_cw310.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/capture/configs/otbn_vertical_modinv_sca_cw310.yaml b/capture/configs/otbn_vertical_modinv_sca_cw310.yaml
index 47df6388..2a54bc51 100644
--- a/capture/configs/otbn_vertical_modinv_sca_cw310.yaml
+++ b/capture/configs/otbn_vertical_modinv_sca_cw310.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/capture/configs/sha3_sca_chip_masks_off.yaml b/capture/configs/sha3_sca_chip_masks_off.yaml
index 687f2079..7854451b 100644
--- a/capture/configs/sha3_sca_chip_masks_off.yaml
+++ b/capture/configs/sha3_sca_chip_masks_off.yaml
@@ -7,6 +7,10 @@ target:
   output_len_bytes: 16
   protocol: "ujson"
   port: "/dev/ttyUSB1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "sw"
 waverunner:
   waverunner_ip: 100.107.71.10
   num_segments: 1
diff --git a/capture/configs/sha3_sca_cw310.yaml b/capture/configs/sha3_sca_cw310.yaml
index 10c6fc25..ca674722 100644
--- a/capture/configs/sha3_sca_cw310.yaml
+++ b/capture/configs/sha3_sca_cw310.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 20
diff --git a/capture/configs/sha3_sca_cw310_masks_off.yaml b/capture/configs/sha3_sca_cw310_masks_off.yaml
index d334f284..d892cffc 100644
--- a/capture/configs/sha3_sca_cw310_masks_off.yaml
+++ b/capture/configs/sha3_sca_cw310_masks_off.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_aes_sca_fvsr_cw305.yaml b/ci/cfg/ci_aes_sca_fvsr_cw305.yaml
index a2f66927..d37f6a0f 100644
--- a/ci/cfg/ci_aes_sca_fvsr_cw305.yaml
+++ b/ci/cfg/ci_aes_sca_fvsr_cw305.yaml
@@ -9,6 +9,10 @@ target:
   baudrate: 115200
   output_len_bytes: 16
   protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 80
diff --git a/ci/cfg/ci_aes_sca_fvsr_cw310.yaml b/ci/cfg/ci_aes_sca_fvsr_cw310.yaml
index 76d3629e..df24a4e9 100644
--- a/ci/cfg/ci_aes_sca_fvsr_cw310.yaml
+++ b/ci/cfg/ci_aes_sca_fvsr_cw310.yaml
@@ -10,6 +10,10 @@ target:
   output_len_bytes: 16
   # protocol: "ujson"
   protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_aes_sca_random_cw305.yaml b/ci/cfg/ci_aes_sca_random_cw305.yaml
index 46e44624..c3fbff5c 100644
--- a/ci/cfg/ci_aes_sca_random_cw305.yaml
+++ b/ci/cfg/ci_aes_sca_random_cw305.yaml
@@ -9,6 +9,10 @@ target:
   baudrate: 115200
   output_len_bytes: 16
   protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 80
diff --git a/ci/cfg/ci_aes_sca_random_cw310.yaml b/ci/cfg/ci_aes_sca_random_cw310.yaml
index 87a3a4d3..24fe1ac6 100644
--- a/ci/cfg/ci_aes_sca_random_cw310.yaml
+++ b/ci/cfg/ci_aes_sca_random_cw310.yaml
@@ -10,6 +10,10 @@ target:
   output_len_bytes: 16
   # protocol: "ujson"
   protocol: "simpleserial"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_ibex_fi_vcc_dummy.yaml b/ci/cfg/ci_ibex_fi_vcc_dummy.yaml
index 3f9678d6..fc841679 100644
--- a/ci/cfg/ci_ibex_fi_vcc_dummy.yaml
+++ b/ci/cfg/ci_ibex_fi_vcc_dummy.yaml
@@ -9,6 +9,10 @@ target:
   baudrate: 115200
   protocol: "ujson"
   port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 fisetup:
   fi_gear: "dummy"
   fi_type: "voltage_glitch"
diff --git a/ci/cfg/ci_kmac_sca_fvsr_cw310_simpleserial.yaml b/ci/cfg/ci_kmac_sca_fvsr_cw310_simpleserial.yaml
index fd6cfc69..8076be0e 100644
--- a/ci/cfg/ci_kmac_sca_fvsr_cw310_simpleserial.yaml
+++ b/ci/cfg/ci_kmac_sca_fvsr_cw310_simpleserial.yaml
@@ -12,6 +12,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_kmac_sca_fvsr_cw310_ujson.yaml b/ci/cfg/ci_kmac_sca_fvsr_cw310_ujson.yaml
index a8cafd86..f9f0d22b 100644
--- a/ci/cfg/ci_kmac_sca_fvsr_cw310_ujson.yaml
+++ b/ci/cfg/ci_kmac_sca_fvsr_cw310_ujson.yaml
@@ -12,6 +12,10 @@ target:
   # protocol: "simpleserial"
   protocol: "ujson"
   port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_kmac_sca_random_cw310_simpleserial.yaml b/ci/cfg/ci_kmac_sca_random_cw310_simpleserial.yaml
index 214d4f70..22593a54 100644
--- a/ci/cfg/ci_kmac_sca_random_cw310_simpleserial.yaml
+++ b/ci/cfg/ci_kmac_sca_random_cw310_simpleserial.yaml
@@ -12,6 +12,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 1
diff --git a/ci/cfg/ci_kmac_sca_random_cw310_ujson.yaml b/ci/cfg/ci_kmac_sca_random_cw310_ujson.yaml
index 57d0f7d4..fc99ed44 100644
--- a/ci/cfg/ci_kmac_sca_random_cw310_ujson.yaml
+++ b/ci/cfg/ci_kmac_sca_random_cw310_ujson.yaml
@@ -12,6 +12,10 @@ target:
   # protocol: "simpleserial"
   protocol: "ujson"
   port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   sampling_rate: 200000000
   num_segments: 1
diff --git a/ci/cfg/ci_sha3_sca_fvsr_cw310_simpleserial.yaml b/ci/cfg/ci_sha3_sca_fvsr_cw310_simpleserial.yaml
index 0b28e56b..0ab64560 100644
--- a/ci/cfg/ci_sha3_sca_fvsr_cw310_simpleserial.yaml
+++ b/ci/cfg/ci_sha3_sca_fvsr_cw310_simpleserial.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_sha3_sca_fvsr_cw310_ujson.yaml b/ci/cfg/ci_sha3_sca_fvsr_cw310_ujson.yaml
index e80ef9ac..d431b849 100644
--- a/ci/cfg/ci_sha3_sca_fvsr_cw310_ujson.yaml
+++ b/ci/cfg/ci_sha3_sca_fvsr_cw310_ujson.yaml
@@ -11,6 +11,10 @@ target:
   # protocol: "simpleserial"
   protocol: "ujson"
   port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 20
diff --git a/ci/cfg/ci_sha3_sca_random_cw310_simpleserial.yaml b/ci/cfg/ci_sha3_sca_random_cw310_simpleserial.yaml
index 91f3fb62..c6a41b97 100644
--- a/ci/cfg/ci_sha3_sca_random_cw310_simpleserial.yaml
+++ b/ci/cfg/ci_sha3_sca_random_cw310_simpleserial.yaml
@@ -11,6 +11,10 @@ target:
   protocol: "simpleserial"
   # protocol: "ujson"
   # port: "/dev/ttyACM4"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 1
diff --git a/ci/cfg/ci_sha3_sca_random_cw310_ujson.yaml b/ci/cfg/ci_sha3_sca_random_cw310_ujson.yaml
index d59b1c96..ef3d52e1 100644
--- a/ci/cfg/ci_sha3_sca_random_cw310_ujson.yaml
+++ b/ci/cfg/ci_sha3_sca_random_cw310_ujson.yaml
@@ -11,6 +11,10 @@ target:
   # protocol: "simpleserial"
   protocol: "ujson"
   port: "/dev/ttyACM_CW310_1"
+  # Trigger source.
+  # hw: Precise, hardware-generated trigger - FPGA only.
+  # sw: Fully software-controlled trigger.
+  trigger: "hw"
 husky:
   samling_rate: 200000000
   num_segments: 1
diff --git a/objs/sca_ujson_fpga_cw310.bin b/objs/sca_ujson_fpga_cw310.bin
index ae3669b8..d1d0cd23 100644
--- a/objs/sca_ujson_fpga_cw310.bin
+++ b/objs/sca_ujson_fpga_cw310.bin
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4815b7893f162f1889300b2f39a78f9475996c4ef666b73662fb348f2bd79d44
-size 206120
+oid sha256:5134c1d8949cf13aef579dd262b393ac18cc261e2f295a0fb5393d960779130b
+size 205904
diff --git a/target/communication/sca_kmac_commands.py b/target/communication/sca_kmac_commands.py
index a39578b5..72614e00 100644
--- a/target/communication/sca_kmac_commands.py
+++ b/target/communication/sca_kmac_commands.py
@@ -18,6 +18,12 @@ def __init__(self, target, protocol: str) -> None:
         if protocol == "ujson":
             self.simple_serial = False
 
+    def _ujson_kmac_sca_cmd(self):
+        # TODO: without the delay, the device uJSON command handler program
+        # does not recognize the commands. Tracked in issue #256.
+        time.sleep(0.01)
+        self.target.write(json.dumps("KmacSca").encode("ascii"))
+
     def init(self, fpga_mode_bit: int):
         """ Initializes KMAC on the target.
         Args:
@@ -27,17 +33,11 @@ def init(self, fpga_mode_bit: int):
             # KmacSca command.
             self._ujson_kmac_sca_cmd()
             # Init command.
-            self.port.write(json.dumps("Init").encode("ascii"))
+            self.target.write(json.dumps("Init").encode("ascii"))
             # FPGA mode.
             time.sleep(0.01)
-            fpga_mode = {"fpga_mode": [fpga_mode_bit]}
-            self.port.write(json.dumps(fpga_mode).encode("ascii"))
-
-    def _ujson_kmac_sca_cmd(self):
-        # TODO: without the delay, the device uJSON command handler program
-        # does not recognize the commands. Tracked in issue #256.
-        time.sleep(0.01)
-        self.target.write(json.dumps("KmacSca").encode("ascii"))
+            fpga_mode = {"fpga_mode": fpga_mode_bit}
+            self.target.write(json.dumps(fpga_mode).encode("ascii"))
 
     def write_key(self, key: list[int]):
         """ Write the key to KMAC.
diff --git a/target/communication/sca_sha3_commands.py b/target/communication/sca_sha3_commands.py
index 5f182842..19c9e362 100644
--- a/target/communication/sca_sha3_commands.py
+++ b/target/communication/sca_sha3_commands.py
@@ -30,8 +30,9 @@ def init(self, fpga_mode_bit: int):
             fpga_mode_bit: Indicates whether FPGA specific KMAC test is started.
         """
         if not self.simple_serial:
+            # Sha3Sca command.
+            self._ujson_sha3_sca_cmd()
             # Init the SHA3 core.
-            self.target.write(json.dumps("Sha3Sca").encode("ascii"))
             self.target.write(json.dumps("Init").encode("ascii"))
             # FPGA mode.
             time.sleep(0.01)
diff --git a/target/communication/sca_trigger_commands.py b/target/communication/sca_trigger_commands.py
new file mode 100644
index 00000000..8e4f04a7
--- /dev/null
+++ b/target/communication/sca_trigger_commands.py
@@ -0,0 +1,40 @@
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+"""Communication interface for the SHA3 SCA application on OpenTitan.
+
+Communication with OpenTitan either happens over simpleserial or the uJson
+command interface.
+"""
+import json
+import time
+from typing import Optional
+
+
+class OTTRIGGER:
+    def __init__(self, target, protocol: str) -> None:
+        self.target = target
+        self.simple_serial = True
+        if protocol == "ujson":
+            self.simple_serial = False
+
+    def select_trigger(self, trigger_source: Optional[int] = 0):
+        """ Select the trigger source for SCA.
+        Args:
+            trigger_source:
+                            - 0: Precise, hardware-generated trigger - FPGA only.
+                            - 1: Fully software-controlled trigger.
+        """
+        if self.simple_serial:
+            self.target.write(cmd="t", data=bytearray([trigger_source]))
+        else:
+            # TODO(#256): without the delay, the device uJSON command handler program
+            # does not recognize the commands.
+            time.sleep(0.01)
+            self.target.write(json.dumps("TriggerSca").encode("ascii"))
+            # SelectTriggerSource command.
+            self.target.write(json.dumps("SelectTriggerSource").encode("ascii"))
+            # Source payload.
+            time.sleep(0.01)
+            src = {"source": trigger_source}
+            self.target.write(json.dumps(src).encode("ascii"))