Ember EM35x系统级芯片ZigBee解决方案
作者: 时间:2009-06-16 17:01 来源:eaw
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: