--- /dev/null
+#include<stdio.h>
+#include<assert.h>
+
+int main()
+{
+ int rt, ach, acl, dsp, pos, efi;
+ int result;
+
+ ach = 0x05;
+ acl = 0xB4CB;
+ dsp = 0x07;
+ result = 0x000C;
+
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %2, $ac1\n\t"
+ "mtlo %3, $ac1\n\t"
+ "extpdp %0, $ac1, 0x03\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(ach), "r"(acl)
+ );
+ pos = dsp & 0x3F;
+ efi = (dsp >> 14) & 0x01;
+ assert(pos == 3);
+ assert(efi == 0);
+ assert(result == rt);
+
+ ach = 0x05;
+ acl = 0xB4CB;
+ dsp = 0x01;
+
+ __asm
+ ("wrdsp %1, 0x01\n\t"
+ "mthi %2, $ac1\n\t"
+ "mtlo %3, $ac1\n\t"
+ "extpdp %0, $ac1, 0x03\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(ach), "r"(acl)
+ );
+ efi = (dsp >> 14) & 0x01;
+ assert(efi == 1);
+
+
+ ach = 0;
+ acl = 0;
+ dsp = 0;
+ result = 0;
+
+ __asm
+ ("wrdsp %1\n\t"
+ "mthi %2, $ac1\n\t"
+ "mtlo %3, $ac1\n\t"
+ "extpdp %0, $ac1, 0x00\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rt), "+r"(dsp)
+ : "r"(ach), "r"(acl)
+ );
+ assert(dsp == 0x3F);
+ assert(result == rt);
+
+ return 0;
+}