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Pre-Boot
DesignWare ARC AXC003 CPU Card User Guide
Version 6323-018
Synopsys, Inc.
May 2017
Default settings of the DIP Switches on the ARC SDP Mainboard
During the board initialization, the pre-bootloader programs the clock dividers and the system
memory map and initializes the DDR3 SDRAM.
The pre-bootloader supports loading an application image from the SPI-flash on the ARC
SDP Mainboard into the SRAM or the DDR3 SDRAM memory of the AXC003 CPU Card. See
the “
Building Bare-Metal Application
” section for instructions on creating the image and for
storing the image in the SPI flash.
Loading an image can be bypassed by setting bit SW2501[3] to
0
. In that case the pre-
bootloader does not load any image, but only performs a board initialization and sets the ARC
core into the
HALT
state.
Note
This operation mode is useful if you want to load your application using the debugger,
but want the board to be initialized automatically. In that case, set the
Boot Mirror
Select
switches to
“Internal ROM,” set the
Boot Mode Select
bits to “Autonomously”
and bypass the image loading. See
Usage of the Mainboard DIP Switches
on page 59
for the exact switch settings.
If loading an image is not bypassed, the last instruction of the Pre-Bootloader is a jump to the
start address of the loaded image, such that the loaded application starts execution.