3 Replies Latest reply on Mar 14, 2011 11:15 AM by content.librarian

    Serial 3-Wire Interface Timing of CYII5SM1300AB

      I need to set the register of CYII5SM1300AB through Serial 3-Wire Interface;


      I have find a few infomation of the serial 3-wire interface, and there is not the interface timing;


      Where can i get it.


      And i can't find how to load the value to the interal register. 


      Another question, the description of Pin 4( S_DATA), it's an digital input/output, so can i read the register value through the serial 3-wire interface, and how to realize it.


      Thanks and please help me!



        • 1. Re: Serial 3-Wire Interface Timing of CYII5SM1300AB

          The Serial interface is 3-wire SPI interface having the device work in half duplex mode so you can read the data as well. The master clock operation should be upto 40MHz.


          There does not seem to be an exact description with the interface timing or an application note with respect to the Image Sensor you have in question. Cypress has SPI interface working demonstrated through various examples using the PSoC Device. You can find the general interface timing in them. A few links on SPI that can be checked for more information are as follows:


               http://www.cypress.com/?docID=27209 – SPI Component Datasheet in the PSoC software.


          http://www.cypress.com/?rID=34609 - AN51234 - PSoC® 1 - PSoC Fundamentals - SPI User Module

          http://www.cypress.com/?rID=48908 - Serial Peripheral Interface (SPI) Slave 2.10


          I hope this helps you to proceed further.

          • 2. Re: Serial 3-Wire Interface Timing of CYII5SM1300AB

            Thanks for you reply!


            You know, i have got some information of SPI interface, but there are four wires for the SPI, and the data is transfered through MOSI and MISO, while there are only one wire of the 3-wire interface in the CYII5SM1300AB, so i have no idea how to transfer the data from the sensor.


            And i have got the datasheet(Rev.C) of the sensor, there are some information of the interface, but it's not enough for writing programme to driver the interface.  


            If there are some more information, please tell me!


            Thanks your kind reply!

            • 3. Re: Serial 3-Wire Interface Timing of CYII5SM1300AB

              Usually the 3-wire is a variant with the bi-directional way of using the interface where the SPI uses one data line instead of two (MOSI and MISO). So this restricts the interface to be half duplex that is used in this case with the following pins for the 3-wire interface:


              Pin 3 S_CLK Input Digital input. Clock signal of serial interface.


              Pin 4 S_DATA Input Digital input/output. Data of serial interface.


              Pin 5 S_EN Input Digital input (active low). Enable of serial 3-wire interface.


              The Pin 6 SER_MODE Input Digital input is to enable the serial mode which is the Serial mode enable (1 = Enable serial 3-wire).


              There does not seem to be a clear documentation as you seek. The maximum tested frequency for the SDATA as the datasheet states is 2.5MHz.