OMAP-L138: Square Wave Distortion in OMAP-L138 StarterWare

Square Wave is getting severely distorted while passing through as shown in the screenshots below. The distortion happens after the ADC:

Square Wave – 10 Hz

Square Wave – 200 Hz

Square Wave – 1 kHz

I am using  OMAP-L138 StarterWare 1.10.04.01, project mcasp_c674x_omapl138_lcdkOMAPL138 — a simple simple pass-through test, very easily reproduced.

Any help or insight into the problem will be appreciated. Thank you!