XRES Pin pull-up resistor recommendation

[Michael_K]

Hello all,

I have a quick question about the XRES pin of the PSoC 4. In the PSoC 4 Hardware Design Considerations it is written that an external pull up resistor is not necessary because the device has an internal pull up resistor. A capacitor can be connected between GND and XRES to avoid glitches. 

I have added the pictures and links.

https://www.infineon.com/dgdl/Infineon-AN88619_PSoC_4_Hardware_Design_Considerations-ApplicationNote...
https://community.infineon.com/t5/Knowledge-Base-Articles/Troubleshooting-PSoC-3-4-5LP-Programming-D...

But on the other hand, the on-board programmers of the Pioneer Kit 042 only have additional pull up resistors and other evaluation kits have capacitors between XRES and GND in addition to the pull up resistor.

https://www.infineon.com/dgdl/Infineon-CY8CKIT-042_Schematic-PCBDesignData-v01_00-EN.pdf?fileId=8ac7...

https://www.infineon.com/dgdl/Infineon-CY8CKIT-145-40XX_Schematic-PCBDesignData-v01_00-EN.pdf?fileId...

Why does Infineon not follow its own recommendations for the kits?
What is the reason?

Best regards

Michael

[Yugandhar · Accepted solution]

Hello,

In CY8CKIT-042 PSoC 4 Pioneer Kit, Reset pin (XRES) has an internal pull-up resistor. However, an external pull-up resistor R10 is connected to the PSoC 4 Reset pin on the kit, which is optional and required only in a noisy system. Please refer to the page 42 in kit guide.
For CY8CKIT-145-40xx kit, the acquisition time is higher for the device to acquire with miniprog. For our kits to work with miniprog we have added the external pull up resistor for reset pin. But for the custom design you may not need this. It depends on your programmer used.

Thanks,
P Yugandhar.