User's Manual

Library L100 Reader User's Guide
4.2 Radio Processing Unit
The Radio Processing Unit (RPU) controls the main features of the L-L100 Reader, such as the RF
channels, the multiplexer and chip decoding.
Figure 4: L-L100 Architecture
DSP
Unit
DSP Boot Flash
Multi-Purpose
D/A Converter
General-Purpose
A/D Conveter
Fast A/D
Converter
Analog Switch
DSP I/O Ports
RF Channels
HPI Interface
The RPU is managed by a Digital Signal Processor (DSP) which performs real-time chip decoding
and manages the reader configuration.
The RPU behaves as a slave as it waits for a host command, executes it and transmits the result.
This command exchange is performed using a specific protocol (HPI protocol) and a specific
interface (HPI interface). This protocol is based on the DSP dual-access memory. The host sends
commands to the DSP by writing to the DSP memory. It then reads the reply in the same memory.
The L-L100 Reader firmware is stored in DSP Flash memory. This firmware is TAGSYS property.
Please refer to “L-L100 Reader Firmware Reference “ for further information about L-L100 Reader
Firmware.
Two RF channels are available but only one can be read at a given time. The DSP controls an
analog switch and connects the RF channel to be read to the Analog/Digital Converter.
4.3 RF Channels and the Multiplexer Architecture
The antenna multiplexer and the RF channels belong to the RPU.
Two RF channels are available. These channels can be enabled independently
Each channel output power can be adjusted up to 4W. The same output level is applied to all the
enabled antennas.
Available phase shift values between antenna 1 and antenna 2 are 0°, 90° 180° and 270°.
On-Off Keying (OOK) and Amplitude Shift Keying (ASK) are available for reader-to-smart label
communication and are managed independently for each RF channel.
18/45 Revision 3.1b April 2003