EM260-RTR datasheet(18/50 Pages) SILICONIMAGE

18 / 50 page

EM260

120-0260-000M Rev 1.1

Page 18

operations, consider an EM260 in a stable network (no joins or leaves) not sending any messages and the Host

is using only one of the 8-byte tokens available to it. Under this scenario, a very rough estimate results in

approximately 330,000 possible set-token operations. The number of possible set-token calls, though, depends

on which tokens are being set, so the ratios of set-token calls for each token play a large factor. A very rough

estimate for the total number of times an App token can bet set is approximately 320,000.

These estimates would typically increase if the EM260 is kept closer to room temperature, since the 1,000

guaranteed write cycles of the Flash is for across temperature.

4.6.2

Flash Information Area (FIA)

The EM260 also includes a separate 1024-byte FIA that can be used for storage of data during manufacturing,

including serial numbers and calibration values. Programming of this special Flash page can only be enabled

using the SIF interface to prevent accidental corruption or erasure. The EmberZNet PRO stack reserves a small

portion of this space for its own use and in addition makes eight manufacturing tokens available to the

application. See document UG100, EZSP Reference Guide, for more information.

4.7

Encryption Accelerator

The EM260 contains a hardware AES encryption engine that is attached to the CPU using a memory-mapped

interface. The CBC-MAC and CTR modes are implemented in hardware, and CCM* is implemented in software.

The first two modes are described in the IEEE 802.15.4-2003 specification. CCM* is described in the ZigBee

Specification (ZigBee document 053474). The EmberZNet PRO stack implements a security API for applications

that require security at the application level.

4.8

nRESET Signal

When the asynchronous external reset signal, nRESET (Pin 13), is driven low for a time greater than 200ns, the

EM260 resets to its default state. An integrated glitch filter prevents noise from causing an inadvertent reset

to occur. If the EM260 is to be placed in a noisy environment, an external LC Filter or supervisory reset circuit

is recommended to guarantee the integrity of the reset signal.

When nRESET asserts, all EM260 registers return to their reset state. In addition, the EM260 consumes 1.5mA

(typical) of current when held in RESET.

4.9

Reset Detection

The EM260 contains multiple reset sources. The reset event is logged into the reset source register, which lets

the CPU determine the cause of the last reset. The following reset causes are detected:

Power-on-Reset

Watchdog

PC rollover

Software reset

Core Power Dip

4.10 Power-on-Reset (POR)

Each voltage domain (1.8V Digital Core Supply VDD_CORE and Pads Supply VDD_PADS) has a power-on-reset

(POR) cell.

The VDD_PADS POR cell holds the always-powered high-voltage domain in reset until the following conditions

have been met:

The high-voltage Pads Supply VDD_PADS voltage rises above a threshold.

The internal RC clock starts and generates three clock pulses.

EM260-RTR 数据表(PDF) 18 Page - Silicon image

EM260-RTR 数据表(HTML) 18 Page - Silicon image

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

数据表下载