User manual

CY4672 Reference Design Guide, Document # 001-16968 Revision ** 75
5. Bridge
5.1 Introduction
This section covers the design goals, architecture, firmware source code modules and configuration
options for the PRoC™ LP bridge. It does not cover the details of the radio subsystem or the config-
uration options that go with it.
5.1.1 Design Features
The CY4672 Reference Design Kit uses PRoC LP CYRF69213 for the bridge. Contact your local
sales representative for more information on the PRoC LP controller.
The architecture was designed to be modular for extendibility and maintainability. It was also
designed so that it could easily be ported from one hardware platform to another assuming the use
of an equivalent microprocessor. Porting to another microprocessor requires more work to account
for the USB hardware support and other hardware specific changes.
Design efforts have been made to reduce the ‘on time’ of the microprocessor and radio to conserve
battery life of attached devices. This includes protocol optimizations along with using sleep features
of the PRoC LP.
5.2 Hardware Overview
The PRoC LP bridge is provided with the RDK. This bridge may be plugged into the USB port on a
PC to provide the Wireless USB bridge functionality. The bridge firmware is written in C and assem-
bly code, and runs on the PDC-9348 USB HID bridge. The rest of this section gives a functional
overview of the bridge firmware.
The bridge connects the remote RoC LP HID’s to a low-speed USB host. This firmware supports
2-way communication with bridge and HID devices configured as transceivers.
Packets similar to standard USB HID packets are encapsulated inside wireless PRoC LP packets,
which also contain a packet header and CRC to help the bridge correctly process the USB HID data
packets. Valid packets are then sent via USB to the USB host.
[+] Feedback