ADSP-BF548_15 Datasheet, PDF (21/102 Pages) Analog Devices – Blackfin Embedded Processor

ADSP-BF542/ADSP-BF544/ADSP-BF547/ADSP-BF548/ADSP-BF549
when the pre-boot has finished and the boot kernel starts the
boot process. However, the HWAIT signal does not toggle in
NAND boot mode. By programming OTP memory, the user
can instruct the preboot routine to also customize the PLL, volt-
age regulator, DDR controller, and/or asynchronous memory
interface controller.
The boot kernel differentiates between a regular hardware reset
and a wakeup-from-hibernate event to speed up booting in the
later case. Bits 6-4 in the system reset configuration (SYSCR)
register can be used to bypass the pre-boot routine and/or boot
kernel in case of a software reset. They can also be used to simu-
late a wakeup-from-hibernate boot in the software reset case.
The boot process can be further customized by “initialization
code.” This is a piece of code that is loaded and executed prior to
the regular application boot. Typically, this is used to configure
the DDR controller or to speed up booting by managing PLL,
clock frequencies, wait states, and/or serial bit rates.
The boot ROM also features C-callable function entries that can
be called by the user application at run time. This enables sec-
ond-stage boot or booting management schemes to be
implemented with ease.
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 supervisor
(O/S kernel, device drivers, debuggers, ISRs) modes of opera-
tion, 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- 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.analog.com/cces.
The other Analog Devices IDE, VisualDSP++, supports proces-
sor families introduced prior to the release of CrossCore
Embedded Studio. This IDE includes the Analog Devices VDK
real time operating system and an open source TCP/IP stack.
For more information visit www.analog.com/visualdsp. Note
that VisualDSP++ will not support future Analog Devices
processors.
EZ-KIT Lite Evaluation Board
For processor evaluation, Analog Devices provides wide range
of EZ-KIT Lite^® evaluation boards. Including the processor and
key peripherals, the evaluation board also supports on-chip
emulation capabilities and other evaluation and development
features. Also available are various EZ-Extenders^®, which are
daughter cards delivering additional specialized functionality,
including audio and video processing. For more information
visit www.analog.com and search on “ezkit” or “ezextender”.
EZ-KIT Lite Evaluation Kits
For a cost-effective way to learn more about developing with
Analog Devices processors, Analog Devices offer a range of EZ-
KIT Lite evaluation kits. Each evaluation kit includes an EZ-KIT
Lite evaluation board, directions for downloading an evaluation
version of the available IDE(s), a USB cable, and a power supply.
The USB controller on the EZ-KIT Lite board connects to the
USB port of the user’s PC, enabling the chosen IDE evaluation
suite to emulate the on-board processor in-circuit. This permits
the customer to download, execute, and debug programs for the
EZ-KIT Lite system. It also supports in-circuit programming of
the on-board Flash device to store user-specific boot code,
enabling standalone operation. With the full version of Cross-
Core Embedded Studio or VisualDSP++ installed (sold
separately), engineers can develop software for supported EZ-
KITs or any custom system utilizing supported Analog Devices
processors.
Rev. E | Page 21 of 102 | March 2014