You can use your burst racial trait to gain an extra attack.
Prerequisite: Xeph.
Benefit: As a swift action, you can expend one or more of your daily uses of burst granted by your xeph heritage to gain one extra attack for 1 round, instead of gaining an increase to your speed. While enjoying your round of celerity, you make one extra attack each round, using your highest base attack bonus, when you take a full attack action.
Source: Complete Psionic, page 59.