AD5144: Quad Digital Pot

Hi guys,

I was looking at the datasheet for AD5144 and I can't find whether it has a linear taper or a logarithmic one. I presume it's a linear 256 step but also able to be programmed to jump +/-6dB in a logarithmic fashion, can anyone help me confirm this.

The datasheet is a bit confusing.

Under Linear Gain Setting Mode of page 27, does it mean that I can adjust both sides of the resistance independently, as in R(a1w1) and R(w1b1)?

Here's the link to the page and datasheet:
http://www.analog.com/en/digital-to...l-potentiometers/ad5144/products/product.html

Thanks