CY7C65215-32LTX UART baud rate and bidirectional issue.

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EfMi_2218266
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Level 2
10 replies posted 5 questions asked 5 replies posted

Hello,

We are using CY7C65215-32LTX in our board as USB2UART bridge, we are using SCB0 only (to get 3M baud) and we face two issues:
a) We configured the system to 3Mbit (including RTS/CTS)but we are getting max baud rate of 2.1Mbit (single direction form UART to USB ) instead of 2.4Mbit  (decreasing all the start stop bits etc from 3Mbit).
We are using updated Windows driver 3.13.0.84

b) Beside the baud rate issue if we are trying to send commands (USB to UART direction) during the 2.1Mbit data (describe in question#1) we are missing several bits .

Thanks you

Efi

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

Sorry for the delay in response. I tried to test the issue at my end. Following are the details of my test environment:

I used TeraTerm as host application. In my test I used SCB0 as transmitter, SCB1 as receiver (configured from Utility) and set 3M as baudrate for both SCBs. I am able to download/receive 2.4Mbits of log from SCB0 to SCB1 without missing any bits. 

Please refer the images of configuration attached to this response.

1) This issue can also be related to the software used. Can you please test your application with TeraTerm?

2) I have reviewed your schematic and found that the XRES pin should be held low for a minimum of 1 µs to reset the USB-Serial controller. Hence, nXRES pin can be tied to VDDD (or VCCIO) through an external resistor of 100 Ω and to ground (GND) through an external capacitor of 0.01 µF(minimum 1-µs time constant), as shown below.

Can you please replace the 100K resistor with 0.01 µF capacitor and check if the issue is resolved.

Meghavi_0-1639758807318.png

Best Regards

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

Please tell me what host application you are using so that we can try to reproduce your issue at our end.

Regards

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Hi Meghavi,

Do you mean which device is connected at the other side of the bridge (beside the PC)?

If yes, the device is our product LTE transceiver, we are using UART as log and commands channel.

Another important input, we compared same setup same test with a different bridge and succeeded to download 2.4Mbit of logs from the device and send commands to the chip without any losses.

 

Thank you

Efi

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

 

By host application, I meant which serial port terminal like Putty, Tera Term or HyperTerminal you are using?

Could you please elaborate "we compared same setup same test with a different bridge and succeeded"? Please let us know which bridge have you used and succeeded to download 2.4Mbit of logs? Is it provided by Infineon or any other manufacturer?

Also, please share the schematic of your application.

 

Best Regards,

Meghavi

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Hi Meghavi,

 

We tested it using our internal applications for logs and commands.

Regarding comparing to a different bridge I meant to a bridge of a different manufacture.
Please see attached CY7C65215 circuit.
*PERPH_1V8 is an always-on domain supplied by an on-board LDO.

Thank you

Best Regards,

Efi

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi,

Can you please let me know how are you configuring the device? Please share the screenshot of the device manager to know how the device is enumerated. 

Also, please share the RX and TX plot.

Regards

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Hi Meghavi,

Please see attached picture for configuration.
What do you mean by RX TX plot? oscilloscope plot?

Thank you

Regards

Efi

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

Yes I meant oscilloscope plot of RX and TX.

Can you please try to configure it with USB Serial Configuration Utility and check whether the issue occurs?

Regards

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Hi Meghavi,

We will try to arrange oscilloscope plot.
We tried several configuration using the "USB serial configuration utility" but none helped, can you advice what is the correct configuration?

From CY7C65215-32LTX datasheet (page 5):

EfMi_2218266_0-1635405387224.png

Is there a relationship (HW or SW) between SCB0 and SCB1 that influence the baud rates?
Are the UART_RX and UART_TX completely asynchronous or is there some mutual influence between them?

Thank you

Efi

 

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

You can refer the USB-Serial Configuration Utility User Guide from the USB-Serial SDK and confirm if you faced same issue after using the utility. 

The data rates will be affected only if the combination mentioned in Table 2 is used. i.e in most cases SPI/I2C in conjunction with UART.

Regards

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Hi Meghavi,
Thank you for your answer.
We configure the device according to the table but it didn't help and the issue reproduce. as I wrote above we also try different configuration but none helped.

I am still trying to arrange an oscilloscope plot of RX, TX,

Can you please explain :
Is there a relationship (HW or SW) between SCB0 and SCB1 that influence the baud rates?
Are the UART_RX and UART_TX completely asynchronous or is there some mutual influence between them?

Thank you
Efi

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Meghavi
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250 replies posted 100 solutions authored 10 likes received

Hi Efi,

Sorry for the delay in response. I tried to test the issue at my end. Following are the details of my test environment:

I used TeraTerm as host application. In my test I used SCB0 as transmitter, SCB1 as receiver (configured from Utility) and set 3M as baudrate for both SCBs. I am able to download/receive 2.4Mbits of log from SCB0 to SCB1 without missing any bits. 

Please refer the images of configuration attached to this response.

1) This issue can also be related to the software used. Can you please test your application with TeraTerm?

2) I have reviewed your schematic and found that the XRES pin should be held low for a minimum of 1 µs to reset the USB-Serial controller. Hence, nXRES pin can be tied to VDDD (or VCCIO) through an external resistor of 100 Ω and to ground (GND) through an external capacitor of 0.01 µF(minimum 1-µs time constant), as shown below.

Can you please replace the 100K resistor with 0.01 µF capacitor and check if the issue is resolved.

Meghavi_0-1639758807318.png

Best Regards

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