/** * @file * @brief RTL22xx board Timer driver * * This uses Timer1 for timing measurments. */ /* * By Ray Xu , modify form Mc9328mxl RTEMS DSP * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.rtems.org/license/LICENSE. */ #include #include #include #include #include "lpc_timer.h" uint32_t g_start; uint32_t g_freq; bool benchmark_timer_find_average_overhead; /* * Set up Timer 1 */ void benchmark_timer_initialize( void ) { g_freq = LPC22xx_Fpclk / 1000; } /* * The following controls the behavior of benchmark_timer_read(). * * AVG_OVEREHAD is the overhead for starting and stopping the timer. It * is usually deducted from the number returned. * * LEAST_VALID is the lowest number this routine should trust. Numbers * below this are "noise" and zero is returned. */ #define AVG_OVERHEAD 0 /* It typically takes X.X microseconds */ /* (Y countdowns) to start/stop the timer. */ /* This value is in microseconds. */ #define LEAST_VALID 1 /* Don't trust a clicks value lower than this */ benchmark_timer_t benchmark_timer_read( void ) { return (T0TC/(LPC22xx_Fpclk/1000000)); /* * Total is calculated by taking into account the number of timer overflow * interrupts since the timer was initialized and clicks since the last * interrupts. */ } void benchmark_timer_disable_subtracting_average_overhead(bool find_flag) { benchmark_timer_find_average_overhead = find_flag; }