EM351 / EM357
General Description
The EM351 and EM357 are fully integrated System-on-Chips that integrate a 2.4 GHz, IEEE 802.15.4-2003-
®
compliant transceiver, 32-bit ARM Cortex™-M3 microprocessor, flash and RAM memory, and peripherals of
use to designers of ZigBee-based systems.
The transceiver uses an efficient architecture that exceeds the dynamic range requirements imposed by the
IEEE 802.15.4-2003 standard by over 15 dB. The integrated receive channel filtering allows for robust co-
existence with other communication standards in the 2.4 GHz spectrum, such as IEEE 802.11-2007 and
Bluetooth. The integrated regulator, VCO, loop filter, and power amplifier keep the external component count
low. An optional high performance radio mode (boost mode) is software-selectable to boost dynamic range.
The integrated 32-bit ARM
®
Cortex™-M3 microprocessor is highly optimized for high performance, low power
consumption, and efficient memory utilization. Including an integrated MPU, it supports two different modes
of operation—privileged mode and user mode. This architecture could allow for separation of the networking
stack from the application code and prevents unwanted modification of restricted areas of memory and
registers resulting in increased stability and reliability of deployed solutions.
The EM351 has 128 kB of embedded flash memory and the EM357 has 192 kB of embedded flash memory. Both
chips have 12 kB of integrated RAM for data and program storage. The Ember software for the EM35x employs
an effective wear-leveling algorithm that optimizes the lifetime of the embedded flash.
To maintain the strict timing requirements imposed by the ZigBee and IEEE 802.15.4-2003 standards, the
EM35x integrates a number of MAC functions, AES128 encryption accelerator, and automatic CRC handling into
the hardware. The MAC hardware handles automatic ACK transmission and reception, automatic backoff
delay, and clear channel assessment for transmission, as well as automatic filtering of received packets. The
Ember Packet Trace Interface is also integrated with the MAC, allowing complete, non-intrusive capture of all
packets to and from the EM35x with Ember’s InSight development tools.
The EM35x offers a number of advanced power management features that enable long battery life. A high-
frequency internal RC oscillator allows the processor core to begin code execution quickly upon waking.
Various deep sleep modes are available with less than 1 µA power consumption while retaining RAM contents.
To support user-defined applications, on-chip peripherals include UART, SPI, TWI, ADC, and general-purpose
timers, as well as up to 24 GPIOs. Additionally, an integrated voltage regulator, power-on-reset circuit, and
sleep timer are available.
Finally, the EM35x utilizes standard Serial Wire and JTAG interfaces for powerful software debugging and
programming of the ARM Cortex™-M3 core. The EM35x integrates the standard ARM system debug components:
Flash Patch and Breakpoint (FPB), Data Watchpoint and Trace (DWT), and Instrumentation Trace Macrocell
(ITM).
Target applications for the EM35x include:
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Smart Energy
Building automation and control
Home automation and control
Security and monitoring
General ZigBee wireless sensor networking
This technical datasheet details the EM35x features available to customers using it with Ember software.
Preliminary
120-035X-000D
ETC [ ETC ]
