Well, run Nero CD-DVD Speed/Nero DiscSpeed [the same thing], and you can find out.
Here’s an example: From the picture posted in this link, you can see the drive being used is an ATAPI DVD A DH20A4P firmware version 9P59. If you have multiple CD/DVD drives, click in the drop-down box to show all of them, and your Pioneer will be listed as the full drive name, followed by the firmware version. Your window will not look exactly like that of the example, but you will still see the drive name and firmware version in the same spot. 