Unavailable ports when using USB

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pastaclub
Junior Member
Posts: 5
Joined: Thu Apr 02, 2020 2:10 pm

Unavailable ports when using USB

Post by pastaclub »

I have questions regarding the unavailable ports when using USB on an XU208 device.

I need USB, so according to the port map, P16A will become unavailable. If I need a 16-bit port, I will thus have to use P16B (correct?)

What confuses me though is the 4-bit ports. For example, the pins belonging to P4A have a yellow background (i.e. unavailable when USB is used) as 8/16/32 bit ports, but a white background in the 4-bit port column. Does it really mean I can use these pins as a 4-bit port (just not anything wider)?

And what if I need more 1-bit ports? Those 4-bit ports have no port names listed in the 1-bit column, so does it really mean they cannot be used as 1-bit ports? In that case, the chips do have really few 1-bit ports.


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mon2
XCore Legend
Posts: 1910
Joined: Thu Jun 10, 2010 11:43 am

Post by mon2 »

Hi. See if my post here helps - the concept of "waxing" for these ports:

viewtopic.php?f=26&t=6676&p=33106&hilit ... ing#p33106
mmar
Experienced Member
Posts: 69
Joined: Fri Jul 05, 2013 5:55 pm

Post by mmar »

Number of bits per port define limit for comunication type. Example 4bit port you can use as 4 x 1bit out ports or 4 x 1bit in ports, but you cant mix in and out. Too communication with 4bit port need write or read all 4bits on every operation.

white background in the 4-bit port column. Does it really mean I can use these pins as a 4-bit port (just not anything wider)? YES