diff --git a/src/machine/machine_esp32_usb.go b/src/machine/machine_esp32_usb.go
new file mode 100644
index 000000000..6f40a48fc
--- /dev/null
+++ b/src/machine/machine_esp32_usb.go
@@ -0,0 +1,45 @@
+//go:build esp32s3 || esp32c3
+
+package machine
+
+import (
+	"device/esp"
+)
+
+type USB_DEVICE struct {
+	Bus *esp.USB_DEVICE_Type
+}
+
+var (
+	_USBCDC = &USB_DEVICE{
+		Bus: esp.USB_DEVICE,
+	}
+
+	USBCDC Serialer = _USBCDC
+)
+
+type Serialer interface {
+	WriteByte(c byte) error
+	Write(data []byte) (n int, err error)
+	Configure(config UARTConfig) error
+	Buffered() int
+	ReadByte() (byte, error)
+	DTR() bool
+	RTS() bool
+}
+
+func (usbdev *USB_DEVICE) Configure(config UARTConfig) error {
+	return nil
+}
+
+func (usbdev *USB_DEVICE) Buffered() int {
+	return int(usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL())
+}
+
+func (usbdev *USB_DEVICE) DTR() bool {
+	return false
+}
+
+func (usbdev *USB_DEVICE) RTS() bool {
+	return false
+}
diff --git a/src/machine/machine_esp32c3.go b/src/machine/machine_esp32c3.go
index eb2a18b5e..f413a8c14 100644
--- a/src/machine/machine_esp32c3.go
+++ b/src/machine/machine_esp32c3.go
@@ -509,102 +509,6 @@ func (uart *UART) writeByte(b byte) error {
 
 func (uart *UART) flush() {}
 
-type Serialer interface {
-	WriteByte(c byte) error
-	Write(data []byte) (n int, err error)
-	Configure(config UARTConfig) error
-	Buffered() int
-	ReadByte() (byte, error)
-	DTR() bool
-	RTS() bool
-}
-
-func initUSB() {
-	// nothing to do here
-}
-
-// USB Serial/JTAG Controller
-// See esp32-c3_technical_reference_manual_en.pdf
-// pg. 736
-type USB_DEVICE struct {
-	Bus *esp.USB_DEVICE_Type
-}
-
-var (
-	_USBCDC = &USB_DEVICE{
-		Bus: esp.USB_DEVICE,
-	}
-
-	USBCDC Serialer = _USBCDC
-)
-
-var (
-	errUSBWrongSize            = errors.New("USB: invalid write size")
-	errUSBCouldNotWriteAllData = errors.New("USB: could not write all data")
-	errUSBBufferEmpty          = errors.New("USB: read buffer empty")
-)
-
-func (usbdev *USB_DEVICE) Configure(config UARTConfig) error {
-	return nil
-}
-
-func (usbdev *USB_DEVICE) WriteByte(c byte) error {
-	if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
-		return errUSBCouldNotWriteAllData
-	}
-
-	usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
-	usbdev.flush()
-
-	return nil
-}
-
-func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
-	if len(data) == 0 || len(data) > 64 {
-		return 0, errUSBWrongSize
-	}
-
-	for i, c := range data {
-		if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
-			if i > 0 {
-				usbdev.flush()
-			}
-
-			return i, errUSBCouldNotWriteAllData
-		}
-		usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
-	}
-
-	usbdev.flush()
-	return len(data), nil
-}
-
-func (usbdev *USB_DEVICE) Buffered() int {
-	return int(usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL())
-}
-
-func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
-	if usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL() != 0 {
-		return byte(usbdev.Bus.GetEP1_RDWR_BYTE()), nil
-	}
-
-	return 0, nil
-}
-
-func (usbdev *USB_DEVICE) DTR() bool {
-	return false
-}
-
-func (usbdev *USB_DEVICE) RTS() bool {
-	return false
-}
-
-func (usbdev *USB_DEVICE) flush() {
-	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
-	for usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
-	}
-}
-
 // GetRNG returns 32-bit random numbers using the ESP32-C3 true random number generator,
 // Random numbers are generated based on the thermal noise in the system and the
 // asynchronous clock mismatch.
diff --git a/src/machine/machine_esp32c3_usb.go b/src/machine/machine_esp32c3_usb.go
new file mode 100644
index 000000000..730967312
--- /dev/null
+++ b/src/machine/machine_esp32c3_usb.go
@@ -0,0 +1,52 @@
+//go:build esp32c3
+
+package machine
+
+import "errors"
+
+var (
+	errUSBWrongSize            = errors.New("USB: invalid write size")
+	errUSBCouldNotWriteAllData = errors.New("USB: could not write all data")
+	errUSBBufferEmpty          = errors.New("USB: read buffer empty")
+)
+
+func initUSB() {}
+
+func (usbdev *USB_DEVICE) WriteByte(c byte) error {
+	if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
+		return errUSBCouldNotWriteAllData
+	}
+	usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
+	usbdev.flush()
+	return nil
+}
+
+func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
+	if len(data) == 0 || len(data) > 64 {
+		return 0, errUSBWrongSize
+	}
+	for i, c := range data {
+		if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
+			if i > 0 {
+				usbdev.flush()
+			}
+			return i, errUSBCouldNotWriteAllData
+		}
+		usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
+	}
+	usbdev.flush()
+	return len(data), nil
+}
+
+func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
+	if usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL() != 0 {
+		return byte(usbdev.Bus.GetEP1_RDWR_BYTE()), nil
+	}
+	return 0, nil
+}
+
+func (usbdev *USB_DEVICE) flush() {
+	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
+	for usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
+	}
+}
diff --git a/src/machine/machine_esp32s3.go b/src/machine/machine_esp32s3.go
index 9c2bd9001..f3ac520d2 100644
--- a/src/machine/machine_esp32s3.go
+++ b/src/machine/machine_esp32s3.go
@@ -308,91 +308,3 @@ func (uart *UART) writeByte(b byte) error {
 }
 
 func (uart *UART) flush() {}
-
-// USB Serial/JTAG Controller for ESP32-S3
-type USB_DEVICE struct {
-	Bus *esp.USB_DEVICE_Type
-}
-
-var (
-	_USBCDC = &USB_DEVICE{
-		Bus: esp.USB_DEVICE,
-	}
-
-	USBCDC Serialer = _USBCDC
-)
-
-func initUSB() {
-	USBCDC.Configure(UARTConfig{BaudRate: 115200})
-}
-
-type Serialer interface {
-	WriteByte(c byte) error
-	Write(data []byte) (n int, err error)
-	Configure(config UARTConfig) error
-	Buffered() int
-	ReadByte() (byte, error)
-	DTR() bool
-	RTS() bool
-}
-
-func (usbdev *USB_DEVICE) Configure(config UARTConfig) error {
-	return nil
-}
-
-func (usbdev *USB_DEVICE) WriteByte(c byte) error {
-	// Host is connected - wait for TX FIFO space with reasonable timeout
-	timeout := 10000 // Generous timeout for connected host
-	for usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 && timeout > 0 {
-		timeout--
-	}
-
-	// Even with host connected, don't hang forever
-	if timeout == 0 {
-		return nil
-	}
-
-	// Write byte to USB Serial/JTAG endpoint
-	usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
-
-	// Trigger transmission
-	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
-
-	return nil
-}
-
-func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
-	for _, c := range data {
-		err = usbdev.WriteByte(c)
-		if err != nil {
-			return n, err
-		}
-		n++
-	}
-	return n, nil
-}
-
-func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
-	// TODO: Implement USB Serial/JTAG input reading
-	return 0, errors.New("ReadByte not implemented")
-}
-
-func (usbdev *USB_DEVICE) Buffered() int {
-	// Return number of bytes available to read
-	return int(usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL())
-}
-
-func (usbdev *USB_DEVICE) DTR() bool {
-	// Data Terminal Ready - not applicable for USB Serial/JTAG
-	return false
-}
-
-func (usbdev *USB_DEVICE) RTS() bool {
-	// Request To Send - not applicable for USB Serial/JTAG
-	return false
-}
-
-func (usbdev *USB_DEVICE) flush() {
-	// Force transmission of any buffered data
-	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
-}
diff --git a/src/machine/machine_esp32s3_usb.go b/src/machine/machine_esp32s3_usb.go
new file mode 100644
index 000000000..c9bfbe7ed
--- /dev/null
+++ b/src/machine/machine_esp32s3_usb.go
@@ -0,0 +1,41 @@
+//go:build esp32s3
+
+package machine
+
+import "errors"
+
+func initUSB() {
+	USBCDC.Configure(UARTConfig{BaudRate: 115200})
+}
+
+func (usbdev *USB_DEVICE) WriteByte(c byte) error {
+	timeout := 10000
+	for usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 && timeout > 0 {
+		timeout--
+	}
+	if timeout == 0 {
+		return nil
+	}
+	usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
+	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
+	return nil
+}
+
+func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
+	for _, c := range data {
+		err = usbdev.WriteByte(c)
+		if err != nil {
+			return n, err
+		}
+		n++
+	}
+	return n, nil
+}
+
+func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
+	return 0, errors.New("ReadByte not implemented")
+}
+
+func (usbdev *USB_DEVICE) flush() {
+	usbdev.Bus.SetEP1_CONF_WR_DONE(1)
+}