Analog Devices VISUALDSP++ 3.5, Manual

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Blackfin Processor Booting
2-4 Vi+ Loader Manual
for 16-Bit Processors
ADSP-BF535 Processor On-Chip Boot ROM
The on-chip boot ROM for the ADSP-BF535 processor does the follow-
ing (
Figure 2-2 ).
1. Sets up Supervisor mode by exiting the
RESET
interrupt service rou-
tine and jumping into the lowest priority interrupt (
IVG15
).
2. Checks whether the
RESET
was a software reset and if so, whether to
skip the entire boot sequence and jump to the start of L2 memory
(
0xF000 0000
) for execution. The on-chip boot ROM does this by
checking bit 4 of the
SYSCR
. If bit 4 is not set, the on-chip boot
ROM performs the full boot sequence. If bit 4 is set, the on-chip
boot ROM bypasses the full boot sequence and jumps to
0xF000
0000
. The register settings are shown in Figure 2-3 .
Figure 2-2. ADSP-BF535 Processors: On-Chip Boot ROM
ADSP-BF535 Processor
4-Byte Header (N)
2
nd
Stage Loader
or
Application
Code
PROM/Flash or SPI Device
2nd Stage Loader
or
Application
Code
N
Bytes
0x0
L2 Memory
(0xF000 0000)
0xEF00 0000
On-Chip
Boot ROM
2
nd
Stage Loader
or
Application
Code