September 2016
24
C
ontrollers
& P
rocessors
Processors with multiple industrial
communication protocols on chip
By Elizabete de Freitas,
Texas Instruments
This article introduces
the Sitara processors which are
tailored for industrial automation and
help to form a complete industrial
automation platform.
Sitara Processor Differentiation
Best-in-class industrial integration
• Scalable from single core to multicore
• ARM Cortex-A8 / Cortex-A9 Cortex-A15
• Integrating multiple industrial communication and
position feedback protocols
AM335x
•ARMCortex –A8
•PRU-ICSS
•GbESwitch,CAN,USB2,…
• 16-bitDDR2 /DDR3
AM437x
•ARMCortex-A9
•PRU-ICSS
•QSPI, GbESwitch,CAN,USB2,…
• 32-bitDDR3
Sampling
Production
AM335x
AM437x
AM572x
AM572x
• 2 xARMCortex-A15,1.5GHz
• 2 xPRU-ICSS
•PCIe,GbESwitch,SATA,CAN,USB3,…
• 2 x 32-bitDDR3
The Sitara processors provide efficient and
scalable architectures for the entire Industrial
Automation system, using the ARM A-series
of cores, including the Cortex-A8, Cortex-A9
and Cortex-A15, all incorporating multiple
industrial communication protocols on a sin-
gle chip. Pin-to-pin and software-compatible
devices in each family of processors, along
with industrial hardware development tools,
software and analog components, provide a
total industrial system solution. Using these
solutions, developers can get to market faster
with their industrial automation designs,
including input/output (I/O) devices, human
machine interface (HMI) and programmable
logic controllers (PLCs).
The Sitara processors combine an ARM A-se-
ries core (single or multiple) with the Indus-
trial Communication Subsystem (PRU-ICSS)
and typical standard industrial interfaces in
a single SoC (System on Chip) to build a dif-
ferentiated scalable architecture. This unique
integration enables small and compact sys-
tems, and as they are manufactured in mod-
ern silicon technologies supporting lowest
power consumption they also enable fanless
designs.
The Sitara AM335x processors are the first
in the family, and offer the best perfor-
mance/peripheral integration/price combina-
tion. With the ARM Cortex A8 scaling from
300MHz to 1GHz and six pin-to-pin compat-
ible devices with multiple speed grades and
temperature ranges, the AM335x devices are
the most popular and flexible of all. The ARM
Cortex A8 is the first processor supporting the
ARMv7-A architecture and has a 2.0 DMIPS/
MHz specification offering up to 2000 DMIPs
for the AM335x.
The Sitara AM437x processors integrate a high
performance Cortex-A9 up to 1GHz that sup-
ports single-cycle vector floating point (VFP)
offering improved performance for floating
point mathematic-intense algorithms such
as motor control. The ARM Cortex A9 fea-
tures an out-of-order speculative issue super-
scalar execution 8-stage pipeline giving 2.50
DMIPS/MHz providing up to 2500 DMIPs for
the AM437x.
The new Sitara AM57x processors feature
a unique heterogeneous architecture that
includes ARM Cortex-A15 cores, C66x DSPs,
Cortex-M4s for maximum performance and
scalability. The best computing performance
is achieved with two types of cores, one or two
ARM Cortex-A15 up to 1.5GHz and one or
two C66x DSPs up to 750MHz. Specific con-
trol functions can be offloaded to two ARM
Cortex-M4 at 213MHz for deterministic,
real-time processing. Two ARM Cortex-A15
cores offer 10500DMIPs which can be com-
plemented with 2x C66x DSP cores adding 48
GMACs/24 GFLOPs providing the AM572x
family with the highest performance in the
Sitara family.
The Industrial Communications Subsystem
(PRU-ICSS) is a proprietary subsystem that
enables the integration of real-time industrial
communications protocols and eliminates the
need for an external ASIC or FPGA, reducing
overall system cost and complexity. The PRU-
ICSS is able to support multiple protocols on
the same hardware using firmware supplied
by TI, through the Industrial Software Devel-
opment Kit, and stacks from industry part-
ners. Real-time Ethernet, fieldbus, interface,
and redundancy protocols are available for
the PRU-ICSS, including certified solutions
for EtherCAT, Profibus, and Profinet, Ether-
Net/IP, SERCOS III, and Powerlink.
In addition the PRU-ICSS include key fea-
tures like direct access to I/O interfaces, to
UART, MII, MDIO and other peripherals. At
its core we have a 32-bit RISC engine that can
be programmed both in C and in ASM while
ensuring 100% deterministic behavior. An
additional advantage of the PRU-ICSS com-
pared to fixed function ASIC or FPGA is the
ability to upgrade devices deployed in the
field with firmware updates.
Figure 1. The different
Sitara processors for
industrial automation
