cpu_clock.h

Go to the documentation of this file.

/*
 * Copyright (C) 2021 Gerson Fernando Budke <nandojve@gmail.com>
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#ifndef CPU_CLOCK_H
#define CPU_CLOCK_H
 
#include <stdint.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
enum {
    CPU_ATXMEGA_CLK_SCALE_DIV1      = 0,
    CPU_ATXMEGA_CLK_SCALE_DIV2      = 1,
    CPU_ATXMEGA_CLK_SCALE_DIV4      = 3,
    CPU_ATXMEGA_CLK_SCALE_DIV8      = 5,
    CPU_ATXMEGA_CLK_SCALE_DIV16     = 7,
    CPU_ATXMEGA_CLK_SCALE_DIV32     = 9,
    CPU_ATXMEGA_CLK_SCALE_DIV64     = 11,
    CPU_ATXMEGA_CLK_SCALE_DIV128    = 13,
    CPU_ATXMEGA_CLK_SCALE_DIV256    = 15,
    CPU_ATXMEGA_CLK_SCALE_DIV512    = 17,
};
 
enum {
    CPU_ATXMEGA_BUS_SCALE_DIV1_1    = 0,
    CPU_ATXMEGA_BUS_SCALE_DIV1_2    = 1,
    CPU_ATXMEGA_BUS_SCALE_DIV4_1    = 2,
    CPU_ATXMEGA_BUS_SCALE_DIV2_2    = 3,
};
 
static inline void atxmega_set_prescaler(uint8_t clk_scale, uint8_t bus_scale)
{
    /* Disable CCP for Protected IO register and set new value
     * Set system clock prescalers to zero. PSCTRL contains A Prescaler
     * Value and one value for and B and C Prescaler
     */
    _PROTECTED_WRITE(CLK.PSCTRL, clk_scale | bus_scale);
}
 
#ifdef __cplusplus
}
#endif
 
#endif /* CPU_CLOCK_H */