LayerscapeのトピックRe: Power Connection to unused block

Power Connection to unused block

deepaknaiknavar — Wed, 09 Nov 2016 12:51:24 GMT

Hi,

I am using LS1021 processor. This Processor has several blocks and its invidual supply rails like USB, Serdes, GPIO.

I have a basic question- If i am not using a USB block in my applixation, should i connect it to a power rail or leave it unconnected?

What is a better approach?

Thanks,

Deepak

Re: Power Connection to unused block

alexander_yakov — Wed, 09 Nov 2016 13:06:14 GMT

Typically, this information is explicitly specified in device datasheet. If it is not explicitly allowed to power down any particular power voltage rail, than this means this voltage rail must be powered even if this functionality is not used.

Re: Power Connection to unused block

Pavel — Thu, 10 Nov 2016 02:16:55 GMT

Look at the LS1021a Design Checklist:

https://www.nxp.com/webapp/Download?colCode=AN4878&location=null&fasp=1&WT_TYPE=Application%20Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation&fileExt=.pdf&Parent_nodeId=1378142598972722203474&Parent_pageType=product

This document contains recommendation for the LS1021a pins connection if USB block or SERDES or GPIO are not used.

Have a great day,
Pavel Chubakov