How can I pan a texture to specific location on a sheet?

I have a sheet of water normals. Is there a way to jump to specific sections of the sheet over time, ie
frame 1 is the first 256x256 pixels of the texture and the next frame is the next set of 256 pixels etc…?
I’m currently using the Shader Graph. I can get the texture to pan quite easily, but its a smooth pan and I specifically want to jump frame to frame so as to make it a smooth animation.

Unfortunately I haven’t used Shader Graph yet but in HLSL and CG there are many ways to do that and I would guess that at least one of them is also possible in Shader Graph. All of them are based on the same idea: have a float value that increases over time but then make it ‘jump’ through integers instead of increasing it gradually. That value can then be used in some formula to determine the texture offset.

trunc, ceil, floor, round:
Functions that find a integer for a float according to different rules.

float f1 = trunc(_Time.y);   // cut off the decimals
float f2 = ceil(_Time.y);   // next integer above
float f3 = floor(_Time.y);   // next integer below
float f4 = round(_Time.y);   // closest integer

int cast:
Converts a float to an int, following the same rules as trunc except that the data type changes here, while trunc still returns a float.

int i = (int)_Time.y;

Gives the remainder of integer division, use it with 1 as second operand and subtract it from the original value to get an integer

float f = _Time.y - _Time.y % 1;