- /** Macro to convert an ISP frequency to a number of timer clock cycles for the software SPI driver */
- #define TIMER_COMP(freq) ((((F_CPU / 8) / freq) / 2) - 1)
+ /** Macro to convert an ISP frequency to a number of timer clock cycles for the software SPI driver. */
+ #define TIMER_COMP(freq) (((F_CPU / 8) / 2 / freq) - 1)
+
+ /** ISP rescue clock speed, for clocking targets with incorrectly set fuses. */
+ #define ISP_RESCUE_CLOCK_SPEED 4000000