1 Reply Latest reply on Mar 13, 2020 1:56 AM by RuzheZ_36

    About CypressPSoC CY8C4147

    noha_3407421

      [Background]

      Customers are trying to use an external clock of 46MHz to improve the accuracy of the communication rate.

       

      To do this, I made the following settings:

      (1) Enable external clock (ExtClk, 46MHz)

      (2) Set IMO to Disable state. (Uncheck the box in Configure System Clocks)

       

      Freezes when writing to Em_EEPROM.

       

      [Inquiry]

      I checked the CDC and referred to the following.

        https://community.cypress.com/docs/DOC-18670

       

      Q.

      At first, HFCLK is connected to IMO and switched to EXTCLK after startup.

      At that time, when updating via uart with bootloader, is the clock of the communication peripheral either ExtClk or IMO?

      Best Regards,

      Harukawa

      =======================================

      (前置き)

      通信レートの精度を上げるため 46MHzの外部クロックをしようとしています。

       

      その時に 外部クロック(ExtClk,46MHz)を有効にし、

      IMOをDisableの状態にします。(Configure System Clocksにてチェックボックス外す)

      Em_EEPROMのWriteを行ったとき、フリーズします。

       

      という現象があり 調べたところ

      https://community.cypress.com/docs/DOC-18670

      を見つけ参照しました。

       

      Q.

      IMOは消さず、ExtClkとIMOを両方Enableにするよう書かれています。

      最初は HFCLKは IMOとつなぎ起動後にEXTCLKに切り替えるとありますが

       

      その時 bootloaderで uart経由でUpdate する場合

      通信ペリフェラルのクロックは ExtClkによるのでしょうか?

      それとも IMOによるのでしょうか?

        • 1. Re: About CypressPSoC CY8C4147
          RuzheZ_36

          Harukawa-san,

           

          As I understand, in customer bootloader poject, HFCLK is configured as EXTCLK, right?

          Only after Bootloader_Start(); called in Bootloader project, updating via uart bootloader can work normally, otherwise the chip won't respond to Bootloader host.

          System Clocks source has been set as EXTCLK before Bootloader_Start(). In this case, when updating via uart with bootloader, the clock of the communication peripheral is ExtClk.

           

          Best Regards,

          Ryan