VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

Loader for ADSP-2126x/2136x/2137x SHARC Processors
/* ------ Setup loop for self-modifying instruction ------- */
I4=0x80004; /* Point to 0x080004 for self-modifying
code inserted by the loader at 0x80004
in bootstream */
R9=pass R9, R11=R12; /* Clear AZ, copy power-on value
of SYSCTL to R11 */
DO 0x80004 UNTIL EQ; /* Set bottom-of-loop address (loopstack)
to 0x80004 and top-of-loop (PC Stack)
to the address of the next
instruction. */
PCSTK=0x80004; /* Change top-of-loop value from the
address of this instruction to
0x80004. */
/* ------------- Setup final DMA parameters --------------- */
R1=0x80000;DM(IISX)=R1; /* Setup DMA to load over ldr */
R2=0x180; DM(CSX)=R2; /* Load internal count */
DM(IMSX)=M6; /* Set to increment internal ptr */
/*----------------- Enable SPI interrupt -------------------*/
bit clr IRPTL SPIHI; /* Clear any pending SPI interr. latch */
bit set IMASK SPIHI; /* Enable SPI receive interrupt */
bit set MODE1 IRPTEN; /* Enable global interrupts */
FLUSH CACHE; /* Remove any kernel instr’s from cache */
/*---------- Begin final DMA to overwrite this code -------- */
ustat1=dm(SPIDMAC);
bit set ustat1 SPIDEN;
dm(SPIDMAC)=ustat1; /* Begin final DMA transfer */
/*------------ Initiate self-modifying sequence ----------- */
JUMP 0x80004 (DB); /* Causes 0x80004 to be the return
VisualDSP++ 4.5 Loader and Utilities Manual 5-31