Analog Devices Blackfin ADSP-BF537 Hardware Reference Manual page 1010

Booting Process
Programs must be sure to save all processor registers modified by
INIT code and to restore them before the INIT code returns. At a
minimum, it is recommended that every INIT code saves the
,
ASTAT RETS
The INIT code can perform push and pop operations through the
stack pointer
scratchpad memory (0xFFB0 0000 – 0xFFB0 0FFF).
Listing 19-4 shows an example INIT code file that demonstrates the setup
of the SDRAM controller.
Listing 19-4. Example INIT Code (SDRAM Controller Setup)
#include <defBF537.h>
.section program;
/*******************************************/
[--SP] = ASTAT;
[--SP] = RETS;
[--SP] = (R7:0);
[--SP] = (P5:0);
/*******************************************/
/*******INIT Code Section*******************/
/*******SDRAM Setup************/
Setup_SDRAM:
P0.L = LO(EBIU_SDRRC);
P0.H = HI(EBIU_SDRRC);
R0 = 0x074A(Z);
W[P0] = R0;
SSYNC;
P0.L = LO(EBIU_SDBCTL);
P0.H = HI(EBIU_SDBCTL);// SDRAM Memory Bank Control Register
R0 = EBCAW_8|EBSZ_16|EBE(Z);//This is just an example!
W[P0] = R0;
SSYNC;
19-24
, and the and
Rx Px
. The boot kernel provides sufficient stack space in
SP
// Save registers onto Stack
// SDRAM Refresh Rate Control Register
ADSP-BF537 Blackfin Processor Hardware Reference
registers used in the INIT code.