Ember 公司的EM351和 EM35是高性能的ZigBee/802.15.4系统级芯片(SoC),集成了2.4 GHz, IEEE 802.15.4-2003兼容的收发器, 32-bit ARM Cortex M3TM微处理器,闪存和RAM存储器以及基于ZigBee系统设计的外设.收发器正常连接高达102dB,经过配置可达109dB,接收灵敏度为-100dBm,可配置到-101dBm,正常模式输出功率+3dBm,可配置成+8dBm,能与Wi-Fi和蓝牙共存.工作电压21.-3.6V,内部有1.8V和1.25V稳压器,可用在智能能量,建筑物自动化和控制,安全监视,通用ZigBee无线传感器网络.本文介绍了EM351和 EM35的主要特性,方框图,典型应用电路和所用材料清单(BOM).

EM351 / EM357: High-Performance, Integrated ZigBee/802.15.4 System-on-Chip

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 M3TM 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 M3TM 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 allows 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 EM35x HAL software 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 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-M3TM 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:

Smart Energy

Building automation and control

Home automation and control

Security and monitoring

General ZigBee wireless sensor networking

EM351和EM357主要特性:

Complete System-on-Chip

32-bit ARM Cortex-M3TM processor

2.4 GHz IEEE 802.15.4-2003 transceiver & lower MAC

128 or 192 kB flash

12 kB RAM memory

AES128 encryption accelerator

Flexible ADC, SPI/UART/TWI serial communications, and general purpose timers

24 highly configurable GPIOs with Schmitt trigger inputs

Industry-leading ARM Cortex-M3TM processor

Leading 32-bit processing performance

Highly efficient Thumb-2 instruction set

Operation at 6, 12 or 24 MHz

Flexible Nested Vectored Interrupt Controller

Low power consumption, advanced management

Rx Current (w/ CPU): 26 mA

Tx Current (w/ CPU, +3 dBm TX): 31 mA

Low deep sleep current, with retained RAM and GPIO: 400 nA with/800 nA without sleep timer

Low-frequency internal RC oscillator for low-power sleep timing

High-frequency internal RC oscillator for fast (100 μsec) processor start-up from sleep

Exceptional RF Performance

Normal mode link budget up to 102 dB; configurable up to 109 dB

-100 dBm normal RX sensitivity; configurable to -101 dBm (1% PER, 20 byte packet)

+3 dB normal mode output power; configurable up to +8 dBm

Robust Wi-Fi and Bluetooth coexistence

Innovative network and processor debug

Ember InSight port for non-intrusive packet trace with Ember InSight tools

Serial Wire/JTAG interface

Standard ARM debug capabilities: Flash Patch & Breakpoint; Data Watchpoint & Trace; Instrumentation Trace Macrocell

Application Flexibility

Single voltage operation: 2.1-3.6 V with internal 1.8 V and 1.25 V regulators

Optional 32.768 kHz crystal for higher timer accuracy

Low external component count with single 24 MHz crystal

Support for external power amplifier

Small 7x7 mm 48-pin QFN package



图1. EM351 和 EM357方框图



图2.EM351 和 EM357典型应用电路

图2的材料清单: