Analog Devices ADSP-BF506F Hardware Reference Manual page 370

System Control ROM Function
P5.L = lo(BFROM_SYSCONTROL);
call(P5);
SP += 12;
(R7:0,P5:0) = [SP++];
unlink;
rts;
The processor's internal scratchpad memory can be used as an alternative
for taking a C struct. Therefore, the stack/frame pointer must be loaded
and passed.
/* 10 = sizeof(ADI_SYSCTRL_VALUES). uimm18m4: 18-bit unsigned
field that must be a multiple of 4, with a range of 8 through
262,152 bytes (0x00000 through 0x3FFFC) */
link sizeof(ADI_SYSCTRL_VALUES)+2;
[--SP] = (R7:0,P5:0);
/* Allocate at least 12 bytes on the stack for outgoing argu-
ments, even if the function being called requires less than this.
*/
SP += -12;
R7 = 0;
R7.L = 0x70B0;
w[FP+-sizeof(ADI_SYSCTRL_VALUES)+offse-
tof(ADI_SYSCTRL_VALUES,uwVrCtl)] = R7;
R7.L = 0x1480;
w[FP+-sizeof(ADI_SYSCTRL_VALUES)+offse-
tof(ADI_SYSCTRL_VALUES,uwPllCtl)] = R7;
R7.L = 0x0004;
w[FP+-sizeof(ADI_SYSCTRL_VALUES)+offse-
tof(ADI_SYSCTRL_VALUES,uwPllDiv)] = R7;
R7.L = 0x0200;
8-28 ADSP-BF50x Blackfin Processor Hardware Reference