The TMS320C6748 fixed- and
floating-point DSP is a low-power
applications processor based on a C674x
DSP core. This DSP
provides significantly lower power than other members of the TMS320C6000™ platform of DSPs.
The device enables original-equipment manufacturers (OEMs) and original-design
manufacturers (ODMs) to quickly bring to market devices with robust operating systems, rich user
interfaces, and high processor performance through the maximum flexibility of a fully integrated,
mixed processor solution.
The device DSP core uses a 2-level cache-based architecture. The level
1 program cache (L1P) is a
32-KB direct mapped cache, and the level 1 data cache (L1D) is a 32-KB 2-way,
set-associative cache. The level 2 program cache (L2P) consists of a 256-KB memory space that is
shared between program and data space. L2 memory can be configured as mapped memory, cache, or
combinations of the two. Although the DSP L2 is accessible by other hosts in the system, an
additional 128KB of RAM shared memory is available for use by other hosts without affecting DSP
performance.
For security-enabled devices, TI’s Basic Secure Boot lets users
protect proprietary intellectual property and prevents external entities from modifying
user-developed algorithms. By starting from a hardware-based “root-of-trust," the secure boot flow
ensures a known good starting point for code execution. By default, the JTAG port is locked down to
prevent emulation and debug attacks; however, the JTAG port can be enabled during the secure boot
process during application development. The boot modules are encrypted while sitting in external
nonvolatile memory, such as flash or EEPROM, and are decrypted and authenticated when loaded during
secure boot. Encryption and decryption protects customers’ IP and lets them securely set up the
system and begin device operation with known, trusted code.
Basic Secure Boot uses either SHA-1 or SHA-256, and AES-128 for boot
image validation. Basic Secure Boot also uses AES-128 for boot image encryption. The secure boot
flow employs a multilayer encryption scheme which not only protects the boot process but also
offers the ability to securely upgrade boot and application software code. A 128-bit
device-specific cipher key, known only to the device and generated using a NIST-800-22 certified
random number generator, is used to protect customer encryption keys. When an update is needed, the
customer uses the encryption keys to create a new encrypted image. Then the device can acquire the
image through an external interface, such as Ethernet, and overwrite the existing code. For more
details on the supported security features or TI’s Basic Secure Boot, see the
.
The peripheral set includes: a 10/100 Mbps Ethernet media access
controller (EMAC) with a management data input/output (MDIO) module; one USB2.0 OTG interface; one
USB1.1 OHCI interface; two I2C Bus interfaces; one multichannel audio
serial port (McASP) with 16 serializers and FIFO buffers; two multichannel buffered serial ports
(McBSPs) with FIFO buffers; two serial peripheral interfaces (SPIs) with multiple chip selects;
four 64-bit general-purpose timers each configurable (one configurable as a watchdog); a
configurable 16-bit host-port interface (HPI); up to 9 banks of general-purpose input/output (GPIO)
pins, with each bank containing 16 pins with programmable interrupt and event generation modes,
multiplexed with other peripherals; three UART interfaces (each with RTS and
CTS); two enhanced high-resolution pulse width modulator (eHRPWM)
peripherals; three 32-bit enhanced capture (eCAP) module peripherals which can be configured as 3
capture inputs or 3 APWM outputs; two external memory interfaces: an asynchronous and SDRAM
external memory interface (EMIFA) for slower memories or peripherals; and a higher speed
DDR2/Mobile DDR controller.
The EMAC provides an efficient interface between the device and a
network. The EMAC supports both 10Base-T and 100Base-TX, or 10 Mbps and 100 Mbps in either half- or
full-duplex mode. Additionally, an MDIO interface is available for PHY configuration. The EMAC
supports both MII and RMII interfaces.
The Serial ATA (SATA) controller provides a high-speed interface to
mass data storage devices. The SATA controller supports both SATA I (1.5 Gbps) and SATA II (3.0
Gbps).
The Universal Parallel Port (uPP) provides a high-speed interface to
many types of data converters, FPGAs, or other parallel devices. The uPP supports programmable data
widths between 8- to 16-bits on both channels. Single-data rate and double-data rate transfers are
supported as well as START, ENABLE, and WAIT signals to provide control for a variety of data
converters.
A video port interface (VPIF) provides a flexible video I/O
port.
The rich peripheral set provides the ability to control external peripheral devices and
communicate with external processors. For details on each peripheral, see the related sections in
this document and the associated peripheral reference guides.
The device has a complete set of development tools for the DSP. These
tools include C compilers, a DSP assembly optimizer to simplify programming and scheduling, and a
Windows debugger interface for visibility
into source code execution.
