diff --git a/Grbl_Esp32/src/Motors/TrinamicDriver.cpp b/Grbl_Esp32/src/Motors/TrinamicDriver.cpp
index a6164e29..901b5a32 100644
--- a/Grbl_Esp32/src/Motors/TrinamicDriver.cpp
+++ b/Grbl_Esp32/src/Motors/TrinamicDriver.cpp
@@ -54,10 +54,10 @@ void TMC2130Stepper::switchCSpin(bool state) {
     // We use the _pinCS to figure out which derived class we have
     switch (this->_pinCS) {
         case 2130:
-            static_cast<Motors::Details::MyTMC2130Stepper*>(this)->_cspin.write(state);
+            static_cast<Motors::Details::MyTMC2130Stepper*>(this)->_cspin.synchronousWrite(state);
             break;
         case 5160:
-            static_cast<Motors::Details::MyTMC5160Stepper*>(this)->_cspin.write(state);
+            static_cast<Motors::Details::MyTMC5160Stepper*>(this)->_cspin.synchronousWrite(state);
             break;
     }
 }
diff --git a/Grbl_Esp32/src/Pin.h b/Grbl_Esp32/src/Pin.h
index 6f1b349b..a90c5737 100644
--- a/Grbl_Esp32/src/Pin.h
+++ b/Grbl_Esp32/src/Pin.h
@@ -125,6 +125,7 @@ public:
     }
 
     inline void write(bool value) const { _detail->write(value); }
+    inline void synchronousWrite(bool value) const { _detail->synchronousWrite(value); }
 
     inline bool read() const { return _detail->read() != 0; }
 
diff --git a/Grbl_Esp32/src/PinMapper.cpp b/Grbl_Esp32/src/PinMapper.cpp
index ee3c1a87..8016ad54 100644
--- a/Grbl_Esp32/src/PinMapper.cpp
+++ b/Grbl_Esp32/src/PinMapper.cpp
@@ -4,9 +4,9 @@
 
 #include <Arduino.h>
 
-// Pin mapping. Pretty straight forward, it's just a thing that stores pins in an array. 
-// 
-// The default behavior of a mapped pin is _undefined pin_, so it does nothing. 
+// Pin mapping. Pretty straight forward, it's just a thing that stores pins in an array.
+//
+// The default behavior of a mapped pin is _undefined pin_, so it does nothing.
 namespace {
     class Mapping {
     public:
@@ -44,7 +44,7 @@ PinMapper::PinMapper() : _mappedId(0) {}
 
 PinMapper::PinMapper(Pin& pin) {
     _mappedId = Mapping::instance().Claim(&pin);
-    
+
     // If you reach this assertion, you haven't been using the Pin class like you're supposed to.
     Assert(_mappedId != 0, "Cannot claim pin. We've reached the limit of 255 mapped pins.");
 }
@@ -77,7 +77,7 @@ PinMapper::~PinMapper() {
 void IRAM_ATTR digitalWrite(uint8_t pin, uint8_t val) {
     auto thePin = Mapping::instance()._mapping[pin];
     if (thePin) {
-        thePin->write(val);
+        thePin->synchronousWrite(val);
     }
 }
 
diff --git a/Grbl_Esp32/src/Pins/I2SOPinDetail.cpp b/Grbl_Esp32/src/Pins/I2SOPinDetail.cpp
index a79284ef..1981cb58 100644
--- a/Grbl_Esp32/src/Pins/I2SOPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/I2SOPinDetail.cpp
@@ -50,11 +50,19 @@ namespace Pins {
 
     PinCapabilities I2SOPinDetail::capabilities() const { return PinCapabilities::Output | PinCapabilities::I2S; }
 
-    void I2SOPinDetail::write(int high) {
+    // The write will not happen immediately; the data is queued for
+    // delivery to the serial shift register chain via DMA and a FIFO
+    void IRAM_ATTR I2SOPinDetail::write(int high) {
         int value = _readWriteMask ^ high;
         i2s_out_write(_index, value);
     }
 
+    // Write and wait for completion.  Not suitable for use from an ISR
+    void I2SOPinDetail::synchronousWrite(int high) {
+        write(high);
+        i2s_out_delay();
+    }
+
     int I2SOPinDetail::read() {
         auto raw = i2s_out_read(_index);
         return raw ^ _readWriteMask;
diff --git a/Grbl_Esp32/src/Pins/I2SOPinDetail.h b/Grbl_Esp32/src/Pins/I2SOPinDetail.h
index a83e4945..1cbd472d 100644
--- a/Grbl_Esp32/src/Pins/I2SOPinDetail.h
+++ b/Grbl_Esp32/src/Pins/I2SOPinDetail.h
@@ -37,6 +37,7 @@ namespace Pins {
 
         // I/O:
         void          write(int high) override;
+        void          synchronousWrite(int high) override;
         int           read() override;
         void          setAttr(PinAttributes value) override;
         PinAttributes getAttr() const override;
diff --git a/Grbl_Esp32/src/Pins/PinDetail.h b/Grbl_Esp32/src/Pins/PinDetail.h
index d6ca4ceb..917f541f 100644
--- a/Grbl_Esp32/src/Pins/PinDetail.h
+++ b/Grbl_Esp32/src/Pins/PinDetail.h
@@ -44,7 +44,8 @@ namespace Pins {
         virtual PinCapabilities capabilities() const = 0;
 
         // I/O:
-        virtual void          write(int high)              = 0;
+        virtual void          write(int high) = 0;
+        virtual void          synchronousWrite(int high) { write(high); }
         virtual int           read()                       = 0;
         virtual void          setAttr(PinAttributes value) = 0;
         virtual PinAttributes getAttr() const              = 0;
diff --git a/Grbl_Esp32/src/Pins/VoidPinDetail.cpp b/Grbl_Esp32/src/Pins/VoidPinDetail.cpp
index 1f3e05f6..d78048ba 100644
--- a/Grbl_Esp32/src/Pins/VoidPinDetail.cpp
+++ b/Grbl_Esp32/src/Pins/VoidPinDetail.cpp
@@ -16,6 +16,7 @@
     along with Grbl_ESP32.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <Arduino.h>  // IRAM_ATTR
 #include "VoidPinDetail.h"
 
 namespace Pins {
@@ -27,10 +28,10 @@ namespace Pins {
         return PinCapabilities::Output | PinCapabilities::Input | PinCapabilities::ISR | PinCapabilities::Void;
     }
 
-    void          VoidPinDetail::write(int high) {}
-    int           VoidPinDetail::read() { return 0; }
-    void          VoidPinDetail::setAttr(PinAttributes value) {}
-    PinAttributes VoidPinDetail::getAttr() const { return PinAttributes::None; }
+    void IRAM_ATTR VoidPinDetail::write(int high) {}
+    int            VoidPinDetail::read() { return 0; }
+    void           VoidPinDetail::setAttr(PinAttributes value) {}
+    PinAttributes  VoidPinDetail::getAttr() const { return PinAttributes::None; }
 
     String VoidPinDetail::toString() { return "NO_PIN"; }