EM35x chips can be designed in as full system-on-chip (SoC) devices for low cost, low power sensors and other devices in the home, or as network co-processor (NCP) devices for more complex applications running on a large applications microprocessor.
System-on-Chip (SoC) vs. Network Co-Processor (NCP)
When used as an SoC, the entire application resides on the EM35x along with the ZigBee PRO software stack, and this can be a very cost-effective design for low cost, low power sensors and other devices in the home; such as light switches, occupancy sensors, contact sensors, lights and simple displays (e.g. In thermostats). More complex products, such as gateways, high-end displays and controllers, or utility meters often have large complex applications running on a large applications microprocessor, and for such devices adding the EM35x as NCP enables certifiable ZigBee applications quickly and easily, maintaining modularity in the system. The NCP runs all of the ZigBee PRO networking stack and is connected to the application host, which runs the application, via SPI or UART using the EZSP protocol. AppBuilder will generate application code for the host processor to enable development of a complete ZigBee certifiable application.
EM35x Network Co-Processor (NCP)
EM35x ZigBee SoCs can be used as a network co-processor (NCP) using the Ember EZSP protocol, supported by EmberZNet PRO 4.3.0 and later. The additional Flash on the EM357 device provides more token space, enabling support for 50 link keys and bindings, necessary for trust center functionality in large ZigBee Smart Energy networks.