VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

Loader for ADSP-21161 SHARC Processors
“Boot Kernel Modification and Loader Issues” on page 4-18
“ADSP-21161 Processor Interrupt Vector Table” on page 4-21
“ADSP-21161 Multi-Application (Multi-DXE) Management” on
page 4-21
Power-Up Booting Process
ADSP-21161 processors include a hardware feature that boot-loads a
small, 256-instruction program into the processor’s internal memory after
power-up or after the chip reset. These instructions come from a program
called boot kernel. When executed, the boot kernel facilitates booting of
user application code. The combination of the boot kernel and application
code comprises the boot-loadable (.ldr) file.
At power-up, after the chip reset, the booting process includes the following
steps.
1. Based on the boot mode, an appropriate DMA channel is automatically
configured for a 256-instruction transfer. This transfer
boot-loads the boot kernel program into the processor memory.
2. The boot kernel runs and loads the application executable code and
data.
3. The boot kernel overwrites itself with the first 256 words of the
application at the end of the booting process. After that, the application
executable code starts running.
The boot mode selection directs the system to prepare the appropriate
boot kernel.
VisualDSP++ 4.5 Loader and Utilities Manual 4-3