sm64pc/lib/src/osAiSetFrequency.c
2019-09-01 15:50:50 -04:00

35 lines
651 B
C

#include "libultra_internal.h"
#include "osAi.h"
#include "hardware.h"
extern s32 D_8033491C;
s32 osAiSetFrequency(u32 freq) {
register u32 a1;
register s32 a2;
register float ftmp;
ftmp = D_8033491C / (float) freq + .5f;
a1 = ftmp;
if (a1 < 0x84) {
return -1;
}
a2 = (a1 / 66) & 0xff;
if (a2 > 16) {
a2 = 16;
}
HW_REG(AI_DACRATE_REG, u32) = a1 - 1;
HW_REG(AI_BITRATE_REG, u32) = a2 - 1;
HW_REG(AI_CONTROL_REG, u32) = 1; // enable dma
return D_8033491C / (s32) a1;
}
// put some extra jr $ra's down there please
static void filler1(void) {
}
static void filler2(void) {
}