EM260-RCM-USART-R Ember, EM260-RCM-USART-R Datasheet - Page 17

• Manufacturer Part Number: EM260-RCM-USART-R
• Description: EM260 RCM BOARD
• Manufacturer: Ember
• Type: Transceiver, 802.15.4/ZigBeer

Specifications of EM260-RCM-USART-R

• Frequency: 2.4GHz
• For Use With/related Products: EM260
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 636-1025

4.4
4.5
4.6
Packet Trace Interface (PTI)
XAP2b Microprocessor
Embedded Memory
The EM260 integrates a true PHY-level PTI for effective network-level debugging. This two-signal interface
monitors all the PHY TX and RX packets (in a non-intrusive manner) between the MAC and baseband modules.
It is an asynchronous 500kbps interface and cannot be used to inject packets into the PHY/MAC interface. The
two signals from the EM260 are the frame signal (PTI_EN) and the data signal (PTI_DATA). The PTI is supported
by InSight Desktop.
The EM260 integrates the XAP2b microprocessor developed by Cambridge Consultants Ltd., making it a true
network processor solution. The XAP2b is a 16-bit Harvard architecture processor with separate program and
data address spaces. The word width is 16 bits for both the program and data sides.
The standard XAP2 microprocessor and accompanying software tools have been enhanced to create the XAP2b
microprocessor used in the EM260. The XAP2b adds data-side byte addressing support to the XAP2 allowing for
more productive usage of RAM and optimized code.
The XAP2b clock speed is 12MHz. When used with the EmberZNet stack, firmware may be loaded into Flash
memory using the SIF mechanism (described in section 7) or over the air or by a serial link using a built-in
bootloader
the assistance of RAM-based utility routines also loaded via SIF.
The EM260 contains embedded Flash and RAM memory for firmware storage and execution. In addition it
partitions a portion of the Flash for Simulated EEPROM and token storage.
4.6.1
The Ember stack reserves a section of Flash memory to provide Simulated EEPROM storage area for stack and
customer tokens. The Flash cell has been qualified for a data retention time of >100 years at room
temperature and is rated to have a guaranteed 1,000 write/erase cycles. Because the Flash cells are qualified
for up to 1,000 write cycles, the Simulated EEPROM implements an effective wear-leveling algorithm which
effectively extends the number of write cycles for individual tokens.
The number of set-token operations is finite due to the write cycle limitation of the Flash. It is not possible to
guarantee an exact number of set-token operations because the life of the Simulated EEPROM depends on
which tokens are written and how often.
The EM260 stores non-volatile information necessary for network operation as well as 8 tokens available to the
Host (see EZSP Reference Guide (120-3009-000)). The majority of internal tokens is only written when the
EM260 performs a network join or leave operation. As a simple ballpark estimate of possible set-token
1
bootloader.
See
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EmberZNet Application Developer's Reference Manual
Simulated EEPROM
Automatic acknowledgement transmission
Automatic transmission of packets from memory
Automatic transmission after backoff time if channel is clear (CCA)
Automatic acknowledgement checking
Time stamping of received and transmitted messages
Attaching packet information to received packets (LQI, RSSI, gain, time stamp, and packet status)
IEEE 802.15.4-2003 timing and slotted/unslotted timing
1
in a reserved area of the Flash. Alternatively, firmware may be loaded via the SIF interface with
Page 17
(120-3021-000) for more information on the
EM260
120-0260-000J