VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

Blackfin Processor Booting
ADSP-BF561/BF566 Processor Boot Streams
The loader utility converts the .dxe file into a boot stream (.ldr) file by
parsing the executable and creating blocks. Each block is encapsulated
within a 10-byte header. The .ldr file is burned into the external memory
device (flash memory, PROM, or EEPROM). The boot ROM reads the
external memory device, parsing the headers and copying the blocks to the
addresses where they reside during program execution. After all the blocks
are loaded, the boot ROM jumps to address 0xFFA0 0000 to execute the
core A program.
� When
code is run on both cores, the core A program is responsible
for releasing core B from the idle state by clearing bit 5 in core A’s
system configuration register. Then core B begins execution at
address 0xFF60 0000.
Multiple .dxe files are often combined into a single boot stream (see
“ADSP-BF561/BF566 Dual-Core Application Management” on
page 2-50 and “ADSP-BF53x and ADSP-BF561/BF566 Multi-Application
(Multi-DXE) Management” on page 2-51).
Unlike the ADSP-BF531/BF532/BF533 processor, the
ADSP-BF561/BF566 boot stream begins with a 4-byte global header,
which contains information about the external memory device. A
bit-by-bit description of the global header is presented in Table 2-7. The
global header also contains a signature in the upper 4 bits that prevents
the boot ROM from reading in a boot stream from a blank device.
Table 2-7. ADSP-BF561/BF566 Global Header Structure
Bit Field Description
0 1 = 16-bit flash, 0 = 8-bit flash; default is 0
1–4 Number of wait states; default is 15
5 Unused bit
6–7 Number of hold time cycles for flash; default is 3
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