Makefiles and library modified to add a new F_CLOCK constant to give the unprescaled master input clock frequency, so that the correct PLL mask can be determined even when the CPU (F_CPU) clock rate is prescaled outside the normal input range of the PLL.

Started to clean up the AVRISP Programmer project code, donated by Opendous Inc.

Demos/AudioInput/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/AudioOutput/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/BluetoothHost/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -166,9 +180,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
-CDEFS += -DNO_STREAM_CALLBACKS
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_HOST_ONLY -DNO_STREAM_CALLBACKS
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 # Place -D or -U options here for ASM sources
 ADEFS = -DF_CPU=$(F_CPU)

Demos/CDC/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/CDCHost/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_HOST_ONLY -DNO_STREAM_CALLBACKS
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/DualCDC/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/Joystick/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/Keyboard/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardFullInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -158,8 +172,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardHost/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_HOST_ONLY -DNO_STREAM_CALLBACKS
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardHostViaInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_HOST_ONLY -DNO_STREAM_CALLBACKS
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardHostWithParser/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -164,8 +178,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_HOST_ONLY -DNO_STREAM_CALLBACKS
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardMouse/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/KeyboardViaInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MIDI/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources
@@ -464,7 +479,7 @@ end:
 
 # Display size of file.
 HEXSIZE = $(SIZE) --target=$(FORMAT) $(TARGET).hex
-EELFSIZE = $(SIZE) $(MCU_FLAG) $(FORMAT_FLAG) $(TARGET).elf
+ELFSIZE = $(SIZE) $(MCU_FLAG) $(FORMAT_FLAG) $(TARGET).elf
 MCU_FLAG = $(shell $(SIZE) --help | grep -- --mcu > /dev/null && echo --mcu=$(MCU) )
 FORMAT_FLAG = $(shell $(SIZE) --help | grep -- --format=.*avr > /dev/null && echo --format=avr )
 

Demos/MassStorage/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -161,8 +175,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MassStorageHost/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -163,8 +177,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_HOST_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/Mouse/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MouseFullInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MouseHost/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_HOST_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MouseHostViaInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_HOST_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MouseHostWithParser/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -164,8 +178,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_HOST_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/MouseViaInt/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -159,8 +173,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/RNDISEthernet/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -171,8 +185,10 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+
 CDEFS += -DNO_DECODE_ETHERNET -DNO_DECODE_ARP -DNO_DECODE_ICMP -DNO_DECODE_IP -DNO_DECODE_TCP -DNO_DECODE_UDP -DNO_DECODE_DHCP
 
 

Demos/StillImageHost/makefile

@@ -89,6 +89,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -162,8 +176,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_HOST_ONLY -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_HOST_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources

Demos/TestApp/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -167,7 +181,8 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES
 CDEFS += -DNUM_BLOCKS=100 -DBLOCK_SIZE=8 -DNUM_HANDLES=20
 
 

Demos/USBtoSerial/makefile

@@ -90,6 +90,20 @@ BOARD  = USBKEY
 F_CPU = 8000000
 
 
+# Input clock frequency.
+#     This will define a symbol, F_CLOCK, in all source code files equal to the 
+#     input clock frequency (before any prescaling is performed). This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_CLOCK = 8000000
+
+
 # Output format. (can be srec, ihex, binary)
 FORMAT = ihex
 
@@ -161,8 +175,9 @@ CSTANDARD = -std=gnu99
 
 
 # Place -D or -U options here for C sources
-CDEFS  = -DF_CPU=$(F_CPU)UL -DBOARD=BOARD_$(BOARD) -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS
-CDEFS += -DUSB_DEVICE_ONLY -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
+CDEFS  = -DF_CPU=$(F_CPU)UL -DF_CLOCK=$(F_CLOCK)UL -DBOARD=BOARD_$(BOARD)
+CDEFS += -DUSE_NONSTANDARD_DESCRIPTOR_NAMES -DNO_STREAM_CALLBACKS -DUSB_DEVICE_ONLY
+CDEFS += -DUSE_STATIC_OPTIONS="(USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)"
 
 
 # Place -D or -U options here for ASM sources