Subversion Repositories NaviCtrl

#include "fifo.h"
#include "main.h"
#include "uart1.h"

u8 fifo_init (fifo_t* f, u8* buffer, const u16 size, u16 putvicsource, u16 getvicsource)
{
        if(f == NULL) return(0);
        f->buffer = buffer;
        f->size = size;
        f->putvicsource = putvicsource;
        f->getvicsource = getvicsource;
        fifo_purge(f);
        return(1);
}

u8 fifo_put(fifo_t *f, const u8 data)
{
        if(f->buffer == 0) return(0);
        if (f->count >= f->size) return(0);     // return 0 in case of FIFO overflow.
        if(f->putvicsource != NO_ITLine) VIC_ITCmd(f->putvicsource, DISABLE);
        *(f->pwrite++) = data;      // copy data byte to buffer
        if(f->pwrite >= f->buffer + f->size) f->pwrite = f->buffer; // start at the begining after reaching the end
        f->count++;
        if(f->putvicsource != NO_ITLine) VIC_ITCmd(f->putvicsource, ENABLE);
        return(1);
}

u8 fifo_get (fifo_t *f, u8 *pdata)
{
        if(f->buffer == 0) return(0);
        if(!f->count) return(0);
        if(f->getvicsource != NO_ITLine) VIC_ITCmd(f->getvicsource, DISABLE);
        *pdata = *(f->pread++);
        if(f->pread >= f->buffer + f->size) f->pread = f->buffer; // start at the begining after reaching the end
        f->count--;
        if(f->getvicsource != NO_ITLine) VIC_ITCmd(f->getvicsource, ENABLE);
        return(1);
}

u8 fifo_get_wait (fifo_t *f, u8 *pdata)
{
        while (!f->count);
        return fifo_get(f, pdata);
}

void fifo_purge(fifo_t* f)
{
        if((f == NULL)) return;
        f->count = 0;
        f->pread = f->buffer;
        f->pwrite = f->buffer;
        return;
}