8 Replies Latest reply on Jan 19, 2020 9:44 PM by hata_3396041

    About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)

    hata_3396041

      Hello

       

      I want to communicate between CY8C5888LT-LP097 and PC using USBUART.

      3V power is input to the CPU power supply.

      ●Does the CY8C5888LT-LP097 step down to 3V internally for 5V input?

      (Can I connect directly to the connector without the need for an external regulator?)

       

      ●What are the required settings in PSoC Creator?

       

      Best Regards

      Hayato

        • 1. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
          hata_3396041

          It would be very helpful if you could answer early.

           

          Hayato

          • 2. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
            PSBU_2325551

            Please check Hardware design guide (page #03-04) for PSOC 5LP available at this link describing about power connections as required:

             

            https://www.cypress.com/documentation/application-notes/an61290-psoc-3-and-psoc-5lp-hardware-design-considerations

            • 3. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
              YoIs_1298666

              Hello,

               

              Thank you very much for your reply.

              We have already considered the operating conditions in "AN61290 PSoC® 3 and PSoC 5LP Hardware Design Considerations.pdf".

              We know that this PSoC5LP power supply separation is perfect and has an available regulators in it.

              We would like to know how to switch between "USB regulator enabled" and "USB regulator bypassed".

              Is our understanding like below correct?

               

              [In case of VUSB_5]

              1. Setting VDDD of "Operating Conditions" in PSoC Creator "System Tabs" to 5V and supplying +5V for VDDD.

              2. If we build the project, the USB power supply is automatically fixed in "VUSB_5" with "USB regulator enabled".

               

              [In case of VUSB_3.3]

              1. Setting VDDD of "Operating Conditions" in PSoC Creator "System Tabs" to 3.3V and supplying +3.3V for VDDD.

              2. If we build the project, the USB power supply is automatically fixed in "VUSB_3.3" with "USB regulator bypassed".

               

              [In case of VUSB_3]

              1. Setting VDDD of "Operating Conditions" in PSoC Creator "System Tabs" to 3V and supplying +3V for VDDD.

              2. If we build the project, the USB power supply is automatically fixed in "VUSB_3" with "USB regulator bypassed".

               

              Best regards,

              Yocchi & Hayato

              • 4. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
                PSBU_2325551

                The USB block can operate in two voltage ranges :

                ■ Standard voltage range – 4.35 V to 5.25 V

                ■ Low voltage range – 3.15 V to 3.45 V

                 

                USB needs a nominal voltage of 3.3 V for its operation. It supports an internal regulator which is used for voltage regulation. While in the Standard Voltage Range, the voltage is regulated to 3.3 V by the internal regulator. While in the Low Voltage Range, the internal regulator should be bypassed.

                The “reg_enable” bit in the USB_USB_CR1 register is used to control the regulator.

                I think by reading this "reg_enable” bit value in code, you can confirm your understanding about USB regulator's mode on setting the power supply values in PSOC Creator.

                Details about this bit will be given in Register TRM of PSOC5LP available on internet at this link:

                https://www.cypress.com/documentation/technical-reference-manuals/psoc-5lp-registers-trm-technical-reference-manual

                • 5. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
                  EktaN_26

                  Hello Yocchi and Hayato,

                   

                  If you want to use the USB regulator enabled mode, then while calling the USBFS_Start(uint8 device, uint mode) function set the mode parameter as USBFS_5V_OPERATION, this will enable the voltage regulator automatically by setting the “reg_enable” bit in the USB_USB_CR1 register.

                   

                  Set the mode parameter as USBFS_3V_OPERATION to disable the voltage regulator.

                   

                  Set the mode parameter as USBFS_DWR_POWER_OPERATION to enable or disable the voltage regulator depending on the power supply.

                   

                  For more details refer to the USBFS.c file generated when building the project.

                   

                  Best Regards

                  Ekta

                   

                  • 6. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
                    YoIs_1298666

                    Hello Ekta-san,

                     

                    Thank you very much.

                    I agree with you but I have two questions.

                     

                    1. Device Number

                        The PSoC5LP has one USB ports. So, is the device number only '0'?

                       

                    2. USBFS_DWR_POWER_OPERATION

                       In case of "USBFS_DWR_POWER_OPERATION" parameter, it is determined by the voltage applied to VDDD to

                       enable or disable the voltage regulator.

                       It is not necessary to configure the operating conditions of "System" tab in PSoC Creator.

                       Why can we configure the voltage in "Operating Conditions"?

                     

                    Best regards,

                    Yocchi & Hayato

                    • 7. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
                      EktaN_26

                      Hello Yocchi,

                       

                      Regarding 1) For the USBFS Component, you can create more than one device descriptor out of which only one will be active at a time.

                      Each device descriptor created will have a different device number. To add a device descriptor, click on 'Descriptor Root' in the tree view and click on add another device. The device number is used to identify which descriptor is sent to the host when PSoC device tries to enumerate.

                       

                      For 2) Setting the 'Operating Conditions' is necessary when using USBFS_DWR_POWER_OPERATION because depending upon the value of VDDD set in the Design Wide Resources the voltage regulator will be enabled or disabled. The function will pick the VDDD value from the Operating Condition set.

                       

                      Best Regards

                      Ekta

                      • 8. Re: About USB terminal regulator of psoc5LP(CY8C5888LT-LP097)
                        hata_3396041

                        Hello Ekta-san

                         

                        Thank you for your reply.

                        We understood this.

                        It was helpful for us.

                         

                        Best Regards

                        Yocchi & Hayato