int time_voltage_change(void)
{
    unsigned int start = 0;
    unsigned int end = 0;

    /* lower voltage */
    ascodec_write(AS3514_CVDD_DCDC3, ascodec_read(AS3514_CVDD_DCDC3) | (3<<0));

    int delay=50;
    while (delay--);   /* let voltage stabilize at lower setting  */

    /* raise voltage */
    ascodec_write(AS3514_CVDD_DCDC3, ascodec_read(AS3514_CVDD_DCDC3) & ~(3<<0));

    start = TIMER2_VALUE;        /* Hack clock */

    /* wait for voltage to come up to 1.2  */
    while (ascodec_read(AS3514_ADC_1) <= 224);   /* 480 *.0025 = 1.20  */
                                                 /* 224 is value for 8LSB's of 480 */
    end = TIMER2_VALUE;        /* Hack clock */

    return (start - end);
}