sm64

A Super Mario 64 decompilation
Log | Files | Refs | README | LICENSE

osAiSetFrequency.c (880B)

      1 #include "libultra_internal.h"
      2 #include "PR/rcp.h"
      3 #include "osint.h"
      4 #include "macros.h"
      5 
      6 s32 osAiSetFrequency(u32 freq) {
      7     register u32 dacRate;
      8 #ifdef VERSION_CN
      9     register u32 bitRate;
     10 #else
     11     register s32 bitRate;
     12 #endif
     13     register float ftmp;
     14     ftmp = osViClock / (float) freq + .5f;
     15 
     16     dacRate = ftmp;
     17 
     18     if (dacRate < AI_MIN_DAC_RATE) {
     19         return -1;
     20     }
     21 
     22     bitRate = (dacRate / 66) & 0xff;
     23     if (bitRate > AI_MAX_BIT_RATE) {
     24         bitRate = AI_MAX_BIT_RATE;
     25     }
     26 
     27     IO_WRITE(AI_DACRATE_REG, dacRate - 1);
     28     IO_WRITE(AI_BITRATE_REG, bitRate - 1);
     29 #ifndef VERSION_CN
     30     IO_WRITE(AI_CONTROL_REG, AI_CONTROL_DMA_ON);
     31 #endif
     32     return osViClock / (s32) dacRate;
     33 }
     34 
     35 #if !defined(VERSION_SH) && !defined(VERSION_CN)
     36 // put some extra jr $ra's down there please
     37 UNUSED static void filler1(void) {
     38 }
     39 
     40 UNUSED static void filler2(void) {
     41 }
     42 #endif