Hi
I'm a little confuse with the default IPU and IPD when working on the OMAP-L138 processor. The OMAP pins are classified according to pin groups such as CP[0], CP[1], CP[2], etc... Thse pin groups are configurable to be internally pulled up or pulled down. However, immediately coming out of reset, there's a default setting assigned to them.
According to the OMAP-L138 Application Processor System documents, only pin groups CP[26], CP[27], CP[28] and CP[29] will be internally pulled down while all other pin groups will be internally pulled up. However, this is not what i seen. I notice that pin GP1[15] in pin group CP[4], which is suppose to be pulled up is pulled down instead. Another case is that pin GP7[12] in pin group CP[28], which is supposed to be pulled down is pulled up.
Does this kind of thing happens often? Is it the case that the default pull ups/downs would not necesarily follow what the document states? Does that mean we should always use strong pull ups/downs (~1kohm) on those lines which is intended to have a default logic even though it is stated in the document whether it is internally pulled up or down?
Hope someone can help advise.
Thanks.
Regards
Colin