// fast clock
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks
// fast clock
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks