diff --git a/artiq/coredevice/i2c.py b/artiq/coredevice/i2c.py
index e9de36161..55148402a 100644
--- a/artiq/coredevice/i2c.py
+++ b/artiq/coredevice/i2c.py
@@ -34,8 +34,8 @@ class PCA9548:
     On the KC705, this chip is used for selecting the I2C buses on the two FMC
     connectors. HPC=1, LPC=2.
     """
-    def __init__(self, dmgr, busno=0, address=0xe8):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, busno=0, address=0xe8, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.busno = busno
         self.address = address
 
@@ -77,8 +77,8 @@ class TCA6424A:
 
     On the NIST QC2 hardware, this chip is used for switching the directions
     of TTL buffers."""
-    def __init__(self, dmgr, busno=0, address=0x44):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, busno=0, address=0x44, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.busno = busno
         self.address = address
 
diff --git a/artiq/coredevice/spi.py b/artiq/coredevice/spi.py
index 6221c8f53..20095a8ff 100644
--- a/artiq/coredevice/spi.py
+++ b/artiq/coredevice/spi.py
@@ -40,8 +40,8 @@ class SPIMaster:
 
     :param channel: RTIO channel number of the SPI bus to control.
     """
-    def __init__(self, dmgr, channel):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, channel, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.ref_period_mu = seconds_to_mu(self.core.coarse_ref_period,
                                            self.core)
         self.channel = channel
diff --git a/artiq/coredevice/ttl.py b/artiq/coredevice/ttl.py
index 9ac12ca48..ef855d6b2 100644
--- a/artiq/coredevice/ttl.py
+++ b/artiq/coredevice/ttl.py
@@ -10,8 +10,8 @@ class TTLOut:
 
     :param channel: channel number
     """
-    def __init__(self, dmgr, channel):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, channel, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.channel = channel
 
         # in RTIO cycles
@@ -82,8 +82,8 @@ class TTLInOut:
 
     :param channel: channel number
     """
-    def __init__(self, dmgr, channel):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, channel, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.channel = channel
 
         # in RTIO cycles
@@ -232,8 +232,8 @@ class TTLClockGen:
 
     :param channel: channel number
     """
-    def __init__(self, dmgr, channel):
-        self.core = dmgr.get("core")
+    def __init__(self, dmgr, channel, core_device="core"):
+        self.core = dmgr.get(core_device)
         self.channel = channel
 
         # in RTIO cycles