ADSP-BF522_15 Datasheet, PDF (20/88 Pages) Analog Devices – Blackfin Embedded Processor

ADSP-BF522/ADSP-BF523/ADSP-BF524/ADSP-BF525/ADSP-BF526/ADSP-BF527
signal. When using HWAIT, the host must still check
ALLOW_CONFIG at least once before beginning to con-
figure the Host DMA Port. After completing the
configuration, the host is required to poll the READY bit in
HOST_STATUS before beginning to transfer data. When
the host sends an HIRQ control command, the boot kernel
issues a CALL instruction to address 0xFFA0 0000. It is the
host's responsibility to ensure that valid code has been
placed at this address. The routine at 0xFFA0 0000 can be a
simple initialization routine to configure internal
resources, such as the SDRAM controller, which then
returns using an RTS instruction. The routine may also by
the final application, which will never return to the boot
kernel.
• Boot from 8-Bit Host DMA (BMODE = 0xF) — In this
mode, the Host DMA port is configured in 8-bit interrupt
mode, with little endian data formatting. Unlike other
modes, the host is responsible for interpreting the boot
stream. It writes data blocks individually into the Host
DMA port. Before configuring the DMA settings for each
block, the host may either poll the ALLOW_CONFIG bit in
HOST_STATUS or wait to be interrupted by the HWAIT
signal. When using HWAIT, the host must still check
ALLOW_CONFIG at least once before beginning to con-
figure the Host DMA Port. The host will receive an
interrupt from the HOST_ACK signal every time it is
allowed to send the next FIFO depths worth (sixteen 32-bit
words) of information. When the host sends an HIRQ con-
trol command, the boot kernel issues a CALL instruction to
address 0xFFA0 0000. It is the host's responsibility to
ensure valid code has been placed at this address. The rou-
tine at 0xFFA0 0000 can be a simple initialization routine
to configure internal resources, such as the SDRAM con-
troller, which then returns using an RTS instruction. The
routine may also by the final application, which will never
return to the boot kernel.
Table 9. Fourth Byte for Large Page Devices
Bit Parameter
Value
Meaning
D1:D0 Page Size
00
(excluding spare area)
01
10
11
1K byte
2K byte
4K byte
8K byte
D2 Spare Area Size
00 8 byte/512 byte
01 _{16 byte/512 byte}
D5:D4 Block Size
(excluding spare area)
00
64K byte
01
128K byte
10
256K byte
11
512K byte
D6 Bus width
00
x8
01 not supported
D3, D7 Not Used for configuration
INSTRUCTION SET DESCRIPTION
The Blackfin processor family assembly language instruction set
employs an algebraic syntax designed for ease of coding and
readability. The instructions have been specifically tuned to pro-
vide a flexible, densely encoded instruction set that compiles to
a very small final memory size. The instruction set also provides
fully featured multifunction instructions that allow the pro-
grammer to use many of the processor core resources in a single
instruction. Coupled with many features more often seen on
microcontrollers, this instruction set is very efficient when com-
piling C and C++ source code. In addition, the architecture
supports both user (algorithm/application code) and super-
visor (O/S kernel, device drivers, debuggers, ISRs) modes
of operation, allowing multiple levels of access to core
processor resources.
The assembly language, which takes advantage of the proces-
sor’s unique architecture, offers the following advantages:
• Seamlessly integrated DSP/MCU features are optimized for
both 8-bit and 16-bit operations.
• A multi-issue load/store modified-Harvard architecture,
which supports two 16-bit MAC or four 8-bit ALU + two
load/store + two pointer updates per cycle.
• All registers, I/O, and memory are mapped into a unified
4G byte memory space, providing a simplified program-
ming model.
• Microcontroller features, such as arbitrary bit and bit-field
manipulation, insertion, and extraction; integer operations
on 8-, 16-, and 32-bit data-types; and separate user and
supervisor stack pointers.
• Code density enhancements, which include intermixing of
16-bit and 32-bit instructions (no mode switching, no code
segregation). Frequently used instructions are encoded
in 16 bits.
DEVELOPMENT TOOLS
Analog Devices supports its processors with a complete line of
software and hardware development tools, including integrated
development environments (which include CrossCore^® Embed-
ded Studio and/or VisualDSP++^®), evaluation products,
emulators, and a wide variety of software add-ins.
Integrated Development Environments (IDEs)
For C/C++ software writing and editing, code generation, and
debug support, Analog Devices offers two IDEs.
The newest IDE, CrossCore Embedded Studio, is based on the
Eclipse^TM framework. Supporting most Analog Devices proces-
sor families, it is the IDE of choice for future processors,
including multicore devices. CrossCore Embedded Studio
seamlessly integrates available software add-ins to support real
time operating systems, file systems, TCP/IP stacks, USB stacks,
algorithmic software modules, and evaluation hardware board
support packages. For more information, visit www.ana-
log.com/cces.
Rev. D | Page 20 of 88 | July 2013