Analog Devices VISUALDSP++ 3.5, Manual

Page: 127 / 166

Vi+ 3.5 Loader Manual 5-3
for 16-Bit Processors
ADSP-218x DSP Loader/Splitter
ADSP-218x DSPs support the following boot modes.
• EPROM booting (BDMA)
• Host booting (IDMA)
• No boot
EPROM Booting – BDMA
In this mode, project data is stored in an 8-bit-wide PROM. After reset,
the DSP follows a special bootstrapping scenario. The DSP reads the
PROM’s contents through the BDMA interface and initializes on-chip
and off-chip memories. The
elfspl21
loader utility generates a PROM
image that contains all project data and loader code.
Refer to “EPROM Booting (BDMA)” on page 5-6 for a detailed discus-
sion of this mode.
Host Booting – IDMA Mode
In this mode, the DSP does not start program execution immediately but
waits passively until a host DSP (such as a microcontroller or another
ADSP-218x part) writes project data into the DSP’s on-chip memory
through the IDMA interface. The
elfspl21
loader processes the project
data, but the data may require post-processing because each type of host
processor requires its individual data format.
Refer to “Host Booting (IDMA)” on page 5-11 for a detailed discussion of
this mode.
No Boot
In this mode, the DSP does not perform booting. After a reset, the DSP
starts program execution directly from the off-chip 24-bit PROM mem-
ory. The splitter capabilities of the
elfspl21
generate a proper PROM hex
file. This option is not often used. You must run
elfspl21.exe
from a
command line.