There is no autochop/region function on the asr that will do that.
Instead you are going to have to go manually in order to chop your beat up as if it were a whole sample.
First, read up in your manual, about internally rerouting your main out to your record/sample line in so you can PLAY your seqeunce for maybe 2 bars long and record/sample it (no loss in quality cause the sample stays digital). Stop the sampling and then assign the recorded loop to a key. Copy PARAMS of that sample, and NOT data, to other root keys so you can edit the loop start/end points anyway you like without physically altering the ACTUAL sample. This type of copying will take up NO extra memory. Root keys is where that sample will play back at the exact same speed at which you sampled it, the original speed. You can choose the root key after you record, the choice will/should pop up on the screen.
If you read up on this and test it out, practice it and get the technique down the way you want, you can do exactly what you are trying to do.
