User's Manual

LRM Radio Module –
Host Interface Specification
Features Summary
Document p/n: 9S02-7954-A001 Rev.A
Cattron-Theimeg Inc. Proprietary and Confidential Page 2-1
2. Features Summary
The LRM design addresses in first place Unity applications requirements. Its interface however is general enough to
allow compatibility to other legacy Cattron products.
• Direct electrical compatibility to Unity RF interface – The interface is defined for natural integration to Unity
product line.
• On-board CPU – The interface is controlled by an on-board Renesas CPU. This CPU controls also the details of
operation of the RF peripherals. This approach has several advantages:
a. Unified host interface definition – A single host interface can be defined for all LRM family members.
b. Low requirement on Host CPU resources – The on-board CPU takes care of most aspects of RF control and
timings. This allows releasing CPU resources (processing time, ROM/RAM space, hardware timers) that
become available for more features addition.
c. Simple Host device drivers - Most of driver firmware complexity is transferred on the radio CPU; the Host
device driver is much simpler, easier to test, and not as critical in regard to timings.
• Minimum buffers/Minimum Delay – Radio CPU firmware is implemented to provide a “almost transparent”
operation; transmission and reception delays are kept to a minimum
• Several interface modes – Several interface modes are supported in order to allow integration with other Cattron
legacy products:
a. Data interface - support for synchronous and asynchronous serial link.
b. Configuration interface - support for I2C, SPI and asynchronous serial access.
• Stand-alone operation for firmware download and production test – The LRM can interface almost directly to a
PC serial port for firmware download and for testing (no need for CPU board); only a TTL/RS232 translator is
required (such as Cattron flashbox).
• Support for advanced feature – The LRM family is designed to support advanced features such as FHSS
(Frequency Hopping Spread Spectrum) and Adaptive Channel Allocation, with minimal impact on Host
firmware.
These different aspects are covered in the rest of this document.