www.cypress.com Document No. 002-14852 Rev. *B 1

1 Introduction

The Cypress CYW43XX family of products provide a highly integrated single-chip solution and offers the lowest

RBOM in the industry for wearables and a wide range of other embedded devices.

These chips implement the highly sophisticated Enhanced Collaborative Coexistence algorithms and hardware

mechanisms, allowing for an extremely collaborative Bluetooth coexistence scheme along with coexistence sup-

port for external radios and a single shared 2.4 GHz antenna for WLAN/BT/ZigBee.

1.1 Cypress Part Numbering Scheme

Cypress is converting the acquired IoT part numbers from Broadcom to the Cypress part numbering scheme. Due

to this conversion, there is no change in form, fit, or function as a result of offering the device with Cypress part

number marking. The table provides Cypress ordering part number that matches an existing IoT part number.

Table 1. Mapping Table for Part Number between Broadcom and Cypress

1.2 Acronyms and Abbreviations

In most cases, acronyms and abbreviations are defined upon first use. For a more complete list of acronyms and

other terms used in Cypress documents, go to: http://www.cypress.com/glossary.

2 IoT Resources

Cypress provides a wealth of data at http://www.cypress.com/internet-things-iot to help you to select the right IoT

device for your design, and quickly and effectively integrate the device into your design. Cypress provides cus-

tomer access to a wide range of information, including technical documentation, schematic diagrams, product bill

of materials, PCB layout information, and software updates. Customers can acquire technical documentation and

software from the Cypress Support Community website (http://community.cypress.com/).

AN214852

Collaborative Coexistence Interface Between Cypress-to-Cypress Solutions

and Cypress-to-third-party Chips

Associated Part Family: CYW43XX

This application note describes collaborative coexistence hardware mechanisms and algorithms of the CYW43XX and how

to connect the COEX wiring between Cypress-to-Cypress solutions or Cypress to a third-party chips. It is intended for

hardware developers interested in using the CYW43XX, CYW4390X, and CYW207XX in their product designs.

Broadcom Part Number Cypress Part Number

BCM43XX CYW43XX

BCM4390X CYW4390X

BCM207XX CYW207XX

BCM43364 CYW43364

BCM43438 CYW43438

BCM43455 CYW43455

BCM4354 CYW4354

BCM43907 CYW43907

BCM43903 CYW43903

BCM20707 CYW20707

Collaborative Coexistence Interface Between Cypress-to-Cypress Solutions and Cypress-to-third-party Chips

www.cypress.com Document No. 002-14852 Rev. *B 2

3 Background

Coexistence problems happen when multiple radios are operating simultaneously in adjacent or overlapping radio

frequency spectrums. This can lead to performance degradation, which is manifested in reduced operating range

and/or lower throughput. Collaborative coexistence provides a methodology by which WLAN/BT/ZigBee can be

collocated on a small form-factor device.

There are three major cases for coexistence problems that range from very severe to less severe:

■ Overlapping frequency spectrum between WLAN, BT, and ZigBee in 2.4 GHz range.

■ Adjacent frequency spectrum

■ Harmonics and inter-modulation distortion

Coexistence mitigation may be achieved by:

■ Hardware

❐ Board layout of RF signal routing and component placement, e.g., antenna isolations, cellular RF and

RFIC components, WLAN/BT/GPS/Zigbee RFIC and RF components, and adding extra filters in the

receivers and transmitters.

■ PHY/Software

❐ Time Domain Multiplexing of radios with time synchronization of radio frames such as using Serial

Enhanced Coexistence Interface (SECI) or Global Coexistence Interface (3-wire).

Coexistence happens at ALL levels — chip, board, antennas, and joint firmware.

4 Before You Begin

It is recommended that the users of this Application Note request the following items from Cypress’s Customer

Support Portal (CSP).

■ A CYW43XX reference design package that contains the schematic and layout.

■ An nvram.txt file template (that includes the COEX parameters) for the reference board.

Note: Contact your Cypress Sales or Engineering support representative FAE for additional information or

clarification.

5 Product Overview

The Cypress CYW43XX WLAN, CYW207XX BT, or WLAN/BT combo chips provide the highest level of integration

for wearables and other consumer/industrial embedded applications. The device includes integrated PMU, IEEE

802.11 MAC/baseband, radio, and Bluetooth for each combo chip. It supports all rates specified in the IEEE

802.11a/b/g/n/ac specifications. It also supports optional antenna diversity for improved RF performance in difficult

environments.

An embedded wireless system-on-a-chip (SoC) CYW43907, which includes an ARM-based processor as well as

WLAN, offers the lowest RBOM in the industry and is uniquely suited for Internet-of-Things (IoT) applications.

For the WLAN section, several alternative host interfaces are included: SDIO, SPI, and PCIe depending on the

products. For the Bluetooth section, a host interface option using high-speed 4-wire UART and PCM digital audio

are provided.

In an integrated single-chip combo solution, the CYW43XX implements highly sophisticated enhanced collabora-

tive coexistence hardware mechanisms and algorithms to enable the WLAN and Bluetooth to operate simultane-

ously and to ensure maximum medium access time, high throughput, and audio quality. Collaborative coexistence

between WLAN and Bluetooth is implemented according to IEEE 802.15.2 Packet Traffic Arbitration (PTA) and

through Cypress's Enhanced Coexistence Interface (ECI). ECI augments PTA signaling by enabling exchange of

additional information required for implementing more advanced collaborative coexistence methods. As a result,

enhanced overall quality for simultaneous voice, video, and data transmission on an embedded system is

achieved.

In a discrete, separated WLAN and Bluetooth solution, or other external radios such as LTE and Zigbee, collabo-

rative coexistence supports through SECI, UART, or 3-wire hardware signaling through a unique set of Serial

Enhanced Coexistence Interface (SECI) or Global Coexistence Interface (GCI) protocols. Using the prioritization

approach between data types and applications, optimum performance can be achieved, resulting in maximum

WLAN throughput, voice quality, and link performance.