Ember公司的EM260是ZigBee網(wǎng)絡(luò)協(xié)處理器,集成了2.4GHz IEEE 802.15.4兼容的無線電收發(fā)器和運(yùn)行在EmberZNet ZigBee堆棧的基于閃存的16位微處理器(XAP2b核).EM260具有和應(yīng)用微處理器快速SPI接口,使得開發(fā)者很容易在他們的微控制器中增加ZigBee網(wǎng)絡(luò)功能.EM260能處理所有時(shí)序和ZigBee網(wǎng)絡(luò)堆棧的資源,使得應(yīng)用微處理器能專一處理應(yīng)用的需求.EM260的目標(biāo)應(yīng)用包括建筑物自動(dòng)化和控制,家庭自動(dòng)化和控制,家庭娛樂控制以及資產(chǎn)跟蹤等.本文提供了EM260包括RF特性在內(nèi)的基本特性,詳細(xì)的方框圖,應(yīng)用電路圖以及參考設(shè)計(jì)所用元器件清單(BOM).

The EM260 from Ember is a ZigBee Network Co-Processor that combines a 2.4GHz IEEE 802.15.4 compliant radio transceiver with a flash-based microprocessor running the EmberZNet ZigBee stack. With a fast SPI-based interface to an application microprocessor, the EM260 allows developers to easily add ZigBee networking to their favorite microcontroller. The EM260 handles all of the timing critical and resource intensive ZigBee networking stack, allowing the application microprocessor to focus solely on application requirements.

The radio in the EM260 provides best-in-class RF performance with excellent sensitivity and transmit power for long range, and 802.11 immunity. A flexible RF interface minimizes external components in configurations with or without external LNA/PAs.

The EM260 provides a SPI-based serial interface (EZSP - EmberZNet Serial Protocol) to the EmberZNet APIs. The ZigBee compliant EmberZNet stack, in combination with the EM260 is optimized for designs requiring long battery life, low external component count, and a reliable, proven, industry-standard networking solution. Innovative on-chip debugging (Insight Port) provides developers with the most advanced view into their application and network available in the industry.

The EM260 integrates a 2.4GHz, IEEE 802.15.4-compliant transceiver with a 16-bit network processor (XAP2b core) to run EmberZNet, the Ember ZigBee-compliant network stack. The EM260 exposes access to the EmberZNet API across a standard SPI module or a UART module, allowing application development on a Host platform. This means that the EM260 can be viewed as a ZigBee peripheral connected over a serial interface. The XAP2b microprocessor is a power-optimized core integrated in the EM260. It contains integrated Flash and RAM memory along with an optimized peripheral set to enhance the operation of the network stack.

The transceiver utilizes an efficient architecture that exceeds the dynamic range requirements imposed by the IEEE 802.15.4-2003 standard by over 15dB. The integrated receive channel filtering allows for co-existence with other communication standards in the 2.4GHz spectrum such as IEEE 802.11g 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 by a further 3dB.

The EM260 contains embedded Flash and integrated RAM for program and data storage. By employing an effective wear-leveling algorithm, the stack optimizes the lifetime of the embedded Flash, and affords the application the ability to configure stack and application tokens within the EM260.

To maintain the strict timing requirements imposed by ZigBee and the IEEE 802.15.4-2003 standard, the EM260 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. In addition, the EM260 allows for true MAC level debugging by integrating the Packet Trace Interface.

An integrated voltage regulator, power-on-reset circuitry, sleep timer, and low-power sleep modes are available. The deep sleep and power down modes draws less than 1μA, allowing products to achieve long battery life.

Finally, the EM260 utilizes the non-intrusive SIF module for powerful software debugging and programming of the network processor.

Target applications for the EM260 include:

• Building automation and control

• Home automation and control

• Home entertainment control

• Asset tracking