qmk_firmware/keyboards/atreus/teensy2/rules.mk

# MCU name
MCU = atmega32u4

# Processor frequency.
#     This will define a symbol, F_CPU, in all source code files equal to the
#     processor frequency in Hz. You can then use this symbol in your source code to
#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
#     automatically to create a 32-bit value in your source code.
#
#     This will be an integer division of F_USB below, as it is sourced by
#     F_USB after it has run through any CPU prescalers. Note that this value
#     does not *change* the processor frequency - it should merely be updated to
#     reflect the processor speed set externally so that the code can use accurate
#     software delays.
F_CPU = 16000000


#
# LUFA specific
#
# Target architecture (see library "Board Types" documentation).
ARCH = AVR8

# Input clock frequency.
#     This will define a symbol, F_USB, in all source code files equal to the
#     input clock frequency (before any prescaling is performed) in Hz. 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_USB = $(F_CPU)

# Interrupt driven control endpoint task(+60)
OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT


# Bootloader selection
#   Teensy       halfkay
#   Pro Micro    caterina
#   Atmel DFU    atmel-dfu
#   LUFA DFU     lufa-dfu
#   QMK DFU      qmk-dfu
#   atmega32a    bootloadHID
BOOTLOADER = halfkay


# If you don't know the bootloader type, then you can specify the
# Boot Section Size in *bytes* by uncommenting out the OPT_DEFS line
#   Teensy halfKay      512
#   Teensy++ halfKay    1024
#   Atmel DFU loader    4096
#   LUFA bootloader     4096
#   USBaspLoader        2048
# OPT_DEFS += -DBOOTLOADER_SIZE=4096