- /* enable SPI, master, 750kHz, XTAL/16 */
- sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR0);
+# if (F_CPU <= 12000000)
+ /* enable SPI, master, 750kHz, XTAL/16 */
+ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR0);
+# else
+ /* enable SPI, master, ~531kHz, XTAL/32 */
+ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR1);
+ sck_spsr = (1 << SPI2X);
+# endif