Cypress CYW4373 Manual

OTP Memory Programming and NVRAM Development - CYW4373
This application note describes the method for creating an nvram.txt file, which is then used to test a new board
design, optimize NVRAM values, and program the one-time programmable (OTP) nonvolatile memory in the
CYW4373 device using the USB or SDIO host interface for WLAN.
Contents
1 Introduction .................................................................. 1
1.1 IoT Resources ..................................................... 1
2 OTP Memory Programming Considerations ................ 1
3 NVRAM Content Development and Memory
Programming Flow ....................................................... 2
4 Customizing nvram.txt File .......................................... 3
4.1 Using nvram.txt File Template ............................ 3
4.2 Editing nvram.txt File ........................................ 12
4.3 Finalizing nvram.txt File .................................... 12
1

Introduction

The Cypress CYW4373 is a single-chip IEEE 802.11a/b/g/n/ac + BT 5.0 device for embedded and IoT applications.
OTP nonvolatile memory is included in the WLAN section of the device to store board-specific information such as
SDIO header, product ID, manufacturer ID, and MAC address. Excluding the internal header information, up to 768
bytes of user accessible OTP memory is available on CYW4373 for WLAN information. The application note provides
OTP programming information for both USB and SDIO host interfaces.
The OTP memory content, along with an editable NVRAM file (nvram.txt file), provides all configuration information
used by the WLAN device driver to initialize and configure CYW4373.
1.1

IoT Resources

Cypress provides a wealth of data at
for your design, and quickly and effectively integrate the device into your design. Cypress provides customer 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/).
2

OTP Memory Programming Considerations

In embedded designs, the host and device are permanently connected, which is typically done using a hardwired USB
or SDIO interface. The only entry which is mandatory to be programmed into the OTP memory is the SDIO header.
This is because there are certain SDIO function settings which are read before the firmware and NVRAM are
downloaded. To properly set these settings, the SDIO header must be programmed into their OTP memory.
Other than the SDIO header, all other NVRAM parameters can be stored in the host's nonvolatile memory rather than
in the OTP memory. For non-embedded devices that may be installed on different hosts, the OTP memory can be
programmed to protect the unique MAC address and prevent end-users from altering the power control parameters,
such as maximum output power.
www.cypress.com
5 Programming OTP Memory ....................................... 12
5.1
5.2 Creating and Editing OTP Binary Map .............. 17
6 Programming CYW4373 OTP
Memory Using iMAX6sx system ................................ 20
6.1 Programming OTP Memory .............................. 21
7 Programming CYW4373 OTP BD Address ............... 25
Document History ............................................................ 26
http://www.cypress.com/internet-things-iot
Document Number. 002-29846 Rev. *A
Author: DK Chen
Associated Part Family: CYW4373
Programming Basic Parameters into
OTP Memory .................................................... 13
to help you to select the right IoT device
AN229846
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