I am currently using ADSP-BF526 in one of my designs. For this I referred ADSP-BF526_ezboard_man_rev.1.2 Schematics. In the Schematics it shown that the reset pin of DSP is getting reset from reset_3V. this is 3.3V signal. All the supplies VDD_INT, VDD_MEM, VDD_EXT are all 1.8V. In the datasheet reset is not mentioned in the power domain table and I am assuming that it comes under VDD_EXT. The Pin is powered by 1.8V and externally 3.3V TTL is being applied. Even though the pins are 3.3V compatible is this configuration OK to use??
In the datasheet I did not get anything on the reset pin as to what voltage levels are to be applied. (or maybe I just missed it blindly). Also on my board hardly anything is being used on 3.3V so is it OK to give the reset pin 1.8V TTL.
Is there any logic that even though a pin is powered by 1.8V but being 3.3V Compatible it can be given 3.3V TTL. Is this valid for some set of pins or all pins?