Eprom Booting (Bdma) - Analog Devices VisualDSP++ 3.5 Manual

ADSP-218x DSP Loader Guide

EPROM Booting (BDMA)

To generate a PROM image for EPROM booting, invoke the
elfspl21.exe
project type to Splitter file and specify options on the Project Options
dialog box's Load page. The command-line syntax is discussed
on page 5-7. For information on how to set up the loader options from
within the VisualDSP++, see online Help.
After , the ADSP-218x DSP loads the 96 bytes from PROM address
RESET
into the first 32 locations of on-chip PM memory. Assuming these
0x0000
96 bytes consist of 32 valid instructions, the DSP executes this piece of
program (preloader) afterwards. Usually 32 instructions are not sufficient
to load the complete project data; therefore, bootstrapping continues and
the preloader loads a set of so-called page loaders beginning at PM address
. After the preloader terminates, the DSP executes the page loaders,
0x0020
which load the project data page by page.
The loader uses a default preloader. You can force the loader with the
switch to use a customized preloader to reduce wait states or to
-uload
implement a boot management scenario (discussed in detail in the Appli-
cation Note EE-146).
Example
The following example lists the default preloader together with its opcode.
Note that the
BWCOUNT
/* standard preloader (32 instructions)
ax0 = 0x0060; dm(0x3fe2) = ax0;
ax0 = 0x0020; dm(0x3fe1) = ax0;
ax0 = 0x0000; dm(0x3fe3) = ax0;
ax0 = 0x0087; dm(0x3fe4) = ax0;
ifc = 0x0008;nop;
imask = 0x0008;
idle;
jump 0x0020; nop; nop; nop;
nop;
5-6
loader from the command line or change the VisualDSP++
value is generated dynamically.
nop; nop; nop;
address
/* BEAD 0x0000:400600 93FE20 */
/* BIAD 0x0002:400200 93FE10 */
/* CTRL 0x0004:400000 93FE30 */
/* BWCOUNT0x0006: 400870 93FE40 */
/* BDMA IRQ 0x0008: 3C008C 000000 */
/* 0x000A: 3C0083 */
/* 0x000B: 028000 */
/* 0x000C: 18020F 000000 */
/* 0x0010: 000000 000000 */
VisualDSP++ 3.5 Loader Manual
for 16-Bit Processors
opcodes */