groupUrl: https://ez.analog.com/audio/
Analog.com Analog Dialogue Wiki English
Analog.com Analog Dialogue Wiki 简体中文
EngineerZone
EngineerZone
  • Site
  • User
  • Site
  • Search
  • User
EngineerZone
EngineerZone
  • Log in
  • Site
  • Search
  • Log in
  • Home
  • Blogs ⌵
    • EZ Spotlight
    • The Engineering Mind
  • Browse ⌵
    • All Groups
    • All Members
  • Support ⌵
    • 3D ToF Depth Sensing
    • A2B
    • Aerospace and Defense (ADEF)
    • Amplifiers
    • Analog Microcontrollers
    • Analysis Control Evaluation (ACE) Software
    • Audio
    • Clock and Timing
    • Condition-Based Monitoring
    • Data Converters
    • Design Tools and Calculators
    • Direct Digital Synthesis (DDS)
    • Embedded Vision Sensing
    • Energy Monitoring and Metering
    • FPGA Reference Designs
    • Industrial Ethernet
    • Interface and Isolation
    • Low Power RF Transceivers
    • MEMS Inertial Sensors
    • Motor Control Hardware Platforms
    • Optical Sensing
    • Power Management
    • Precision Technology Signal Chains
    • Processors and DSP
    • Reference Designs
    • RF and Microwave
    • Signal Chain Power (SCP)
    • Switches/Multiplexers
    • Temperature Sensors
    • Video
    • Wide Band RF Transceivers
    • Wireless Sensor Networks Reference Library
  • About EZ
  • More
  • Cancel
  • 主页
  • 浏览 ⌵
    • 收件箱
    • 个人设置
    • 会员
    • 专区列表
  • 论坛专区 ⌵
    • 放大器专区
    • 精密转换器专区
    • 音频专区
    • ADE电能计量专区
    • MEMS和传感器专区
    • 接口和隔离专区
    • Power 中文专区
    • ADUC微处理器专区
    • 锁相环专区
    • 开关和多路复用器专区
    • 温度传感器
    • 基准电压源专区
    • 资源库
    • 论坛使用指南
    • 技术支持参考库
    • 在线研讨会
    • 论坛社群活动
    • 论坛激励活动
  • More
  • Cancel
Audio
Audio
Documents AD1937: Failure due to  I2C interface
  • Q&A
  • Documents
  • Video/Images
  • Tags
  • Managers
  • More
  • Cancel
  • New
Audio requires membership for participation - click to join
  • +Documents
  • +AD1853: FAQ
  • +AD73322: FAQ
  • +AD73311: FAQ
  • +AD73360: FAQ
  • +32-bit Audio Converters: FAQ
  • +AD1835: FAQ
  • +AD1836: FAQ
  • +AD1836A: FAQ
  • +AD1845: FAQ
  • +AD1852: FAQ
  • +AD1854: FAQ
  • +AD1862: FAQ
  • +AD1871: FAQ
  • +AD1877: FAQ
  • +AD1881: FAQ
  • +AD1896: FAQ
  • -AD1937: FAQ
    • AD1937: Failure due to  I2C interface
  • +ad1938: FAQ
  • +AD1939: FAQ
  • +AD193x: FAQ
  • +AD1955: FAQ
  • +ad1970: FAQ
  • +AD1974: FAQ
  • +AD1981: FAQ
  • +AD1986: FAQ
  • +AD1992: FAQ
  • +adau1381: FAQ
  • +ADAU1472: FAQ
  • +ADAU1761: FAQ
  • +ADAU1772: FAQ
  • +ADAU1966: FAQ
  • +ADMP441Z: FAQ
  • +ADMP504: FAQ
  • +CODEC: FAQ
  • +Digital Microphone: FAQ
  • +EVAL-MICT5818Z: FAQ
  • +HD Audio Codecs: FAQ
  • +MEMS mics: FAQ
  • +Power supplies, capacitors, and application schematics: FAQ
  • +REGEN and THERM: FAQ
  • +SigmaStudio: FAQ
  • +ssm2166: FAQ
  • +SSM2250: FAQ
  • +SSM2302: FAQ
  • +SSM2306: FAQ
  • +ssm2311: FAQ
  • +ssm2518: FAQ
  • +SSM2529: FAQ
  • +ssm2602: FAQ
  • +SSM2603: FAQ

AD1937: Failure due to  I2C interface

Q 

We have an audio device built around the ADAU1445-DSP and the AD1937 CODEC. 
The ADAU1445-DSP is the clock master.
Both of them are controlled on the same I2C bus by a processor, with a
software, (‘bit bang’), I2C.
7 bit address of the AD1937 is 0x04 and the ADAU1445 is 0x38.
When our processor gets busy, the I2C is a low priority and gets interrupted.
We can see on the oscilloscope that sometimes midway through an I2C
transaction, both the SCL and the SDA ports stay low for about 40ms.
This within the I2C specs as there’s no limit on clock or data speed, the I2C
protocol analyzer, (http://www.totalphase.com/products/beagle_ism/ ),  shown no
errors, took us a while to notice the 40ms delay in the transaction.
When this 40ms both signal low happens, the AD1937’s AD clocks lock up:
- Both clock pins, (ALRCLK and ALRCLK), turn from normally configured input to
output,
(and as our system is normally configured as CODEC slave, we have very loud
noise sent on all AD channels with two out of phase clock sources).
- I2C communication is working OK, can write and read all registers.
- Verified, that all written commands into registers are correctly executed,
except the AD clock pin directions, we can even change the ABCLK rate.
Only Hardware reset will release the AD1937 from this locked state.   We are
wondering if this problem is known to AD, or you can see something we are
missing, (and possibly on the wrong track).

 

A 

We have done a comprehensive analysis of Stand Alone mode in the AD193x family
of parts. Given the fact that the customer is using the AD1937, I will refer to
the I2C pins, with respect to the corresponding stand alone mode pins.

There are 4 pins total that are used for Stand Alone mode: ADDR0, ADDR1, SCL,
and SDA, see the table 12 n the datasheet.

Usually, it would be assumed that an IC would look at the Stand Alone mode port
once at startup and stay fixed, in or out, of Stand Alone mode until the next
reset. However, it appears from bench testing that the AD1937 will go into
Stand Alone mode if ADDR0, ADDR1 and SCL are all held Low for more than 4 mS,
with the state of SDA setting the ADC Clock ports to Master or Slave. At the
same time, the Stand Alone mode will revert to *default* state if the pin
conditions above are removed.
If the customer is using ADDR 00, two of the three pins are already low. If the
SDA and SCL pins are held low for 40 mS, this would certainly put the part in
Stand Alone Slave mode, and when the SDA and SCL pins come back high, the part
will be left in default. The easiest solution would be to change the I2C
address by pulling either or both ADDR0/1 pins high; the AD1937 will never go
into Stand Alone mode.
P.S. After some lengthy testing, it turns out that the part does not lose its
register settings when it goes into and comes out of Stand Alone mode.

  • ad1937
  • Share
  • History
  • More
  • Cancel
Comments
Anonymous
Related
 
社交网络
快速链接
  • 关于ADI
  • Partners
  • 模拟对话
  • 职业
  • 联系我们
  • 投资信息
  • 新闻中心
  • 质量和可靠性
  • 办事处与代理商
  • Analog Garage
语言
  • English
  • 简体中文
  • 日本語
  • Руccкий
电子快讯

欲获得最新ADI产品、设计工具、培训与活动的相关新闻与文章,请从我们的在线快讯中选出您感兴趣的产品类别,每月或每季度都会发送至您的收件箱。

订阅
Switch to mobile view
Analog Logo
© 1995 - 2022 Analog Devices, Inc. All Rights Reserved 沪ICP备09046653号-1
  • ©
  • 1995 - 2022 Analog Devices, Inc. All Rights Reserved
  • 沪ICP备09046653号-1
  • 网站地图
  • 隐私和保密政策
  • 隐私设置
  • 使用条款
 
Social
Quick Links
  • About ADI
  • Partners
  • Analog Dialogue
  • Careers
  • Contact us
  • Investor Relations
  • News Room
  • Quality & Reliability
  • Sales & Distribution
  • Analog Garage
Languages
  • English
  • 简体中文
  • 日本語
  • Руccкий
Newsletters

Interested in the latest news and articles about ADI products, design tools, training and events? Choose from one of our 12 newsletters that match your product area of interest, delivered monthly or quarterly to your inbox.

Sign Up
Switch to mobile view
Analog Logo
© 1995 - 2022 Analog Devices, Inc. All Rights Reserved 沪ICP备09046653号-1
  • ©
  • 1995 - 2022 Analog Devices, Inc. All Rights Reserved
  • 沪ICP备09046653号-1
  • Sitemap
  • Privacy & Security
  • Privacy Settings
  • Terms of use
EngineerZone Uses cookies to ensure you get the best experience in our community. For more information on cookies, please read our Privacy & Security Statement.