TMS320F28335: Interface level of PD pin

From the figure you have copied from the F2833x datahsheet, PD (power detect) is connected to the VDDIO rail of the device.  In this case VDDIO is specified in the datasheet here: http://www.ti.com/product/TMS320F28335/datasheet/specifications#sprs439roc as 3.3V +/- 5%.  As shown in the diagram tying PD to the VDDIO power plane is used so that the emulator can detect if there is a power loss to the device.

Best,

Matthew