Saw this on PSR Tutorial site...........

"There are two ways to access the arpeggiator.
1. Select a Voice and then press Direct Access then press the Harmony/Arp button

2. Select a Voice and while in the Voice list screen, press the Voice Set button at the bottom of the screen... then Tab left to the Harmony/Arp page

Once in the arpeggiator screen you can select from the Categories of Harmony , Echo and Arpeggio Types. There is a Detail tab you can open and set the arp to auto, R1 or R2 and adjust the arp to play at the same volume as when the arp is turned off. (this is important)

3. It is a good idea to creating a LIVE CONTROL assignment as follows:

Knob 1 = Arp Velocity
Knob 2 = Arp Note Gate Time (this actually changes the length of the notes the arp is playing. You will find that adjusting knob 2 between the 9:00 o'clock and 12:00 o'clock position will change the arp playback considerably. (unfortunatelky there is no way to save these knob settings in a registration... I asked Yamaha about that... it can't be done)

4. You can also set the Arpeggio Hold parameter if you want the arp to continue to play when you lift your fingers from the keys (this is sometimes useful) You can assign this function to a foot pedal so you can turn the Arp Hold on and off as desired.

Function --> Utility --> Config2 --> Arpeggio --> Hold -->On/Off

Learning to play the arps takes some practice.

5. Remember you can always get to the Arp screen by pressing Direct Access then press the Arp button. You can change arps on the fly. And you can select arps from each category and go back and forth between the categories (the last selection in each category is memorized so you can switch between different arps real-time)

6. If you have reach the arp page by selecting Voice Set, you can save the Voice with the arp you have selected as a User Voice. So it is possible to create a whole collection of User Voices that play the arp of your choice.

7. You can save an Arp to each Voice in OTS (either turned on or off)

8. You can also save an arp to a Voice using a registration"

demo at 6:08

https://www.youtube.com/watch?v=NDWTAjs7qeI