#include <sound.h>
#include <timer.h>
#include <aduc812.h>
#include <common.h>
#include <stdint.h>

unsigned char delay[2];
unsigned char current_ena;


void write_ena(unsigned char value)
{
    WriteMax(4, value);
}

void T1_ISR(void) __interrupt(3)
{
    current_ena = ~current_ena;
    write_ena(current_ena);

    TH1 = delay[1];
    TL1 = delay[0];
}

void PlaySound(unsigned int t, unsigned int frequency)
{
    uint16_t tmp = 460791/frequency;
    uint8_t* ptr = (uint8_t*)&tmp;

    delay[0] = 0xFF - ptr[0];
    delay[1] = 0xFF - ptr[1];

    current_ena = 0x18;

    TH1 = delay[1];
    TL1 = delay[0];

    SetVector(0x201B, (void*)T1_ISR);

    TMOD |= 0x10;
    TCON |= 0x40;

    DelayMs(t);

    TCON &= 0x3F;

    ET1 = 1;
    EA  = 1;
}