In the Cypress NAND flash device datasheet, one of the footnotes says: “These pins are assigned as VCC/VSS function, only to comply with ONFI specification. These pins should be connected to power supply or ground (as designated) following the ONFI specification; however, they may not be bonded internally.” Are they connected internally or not?
In Cypress NAND flash devices, VCC (35 and 39) and VSS (25 and 48) pins can remain unconnected (floating/open) from the PCB for the 48-pin TSOP1 package. Also, VCC (G4) and VSS (D3 and F7) solder ball can remain unconnected (floating/open) from the PCB for the 63-ball BGA package (refer to the figures below).
These pins are assigned as the VCC/VSS function, only to comply with ONFI specification. In all our NAND flash devices including MS-1 NAND flash family, MS-2 NAND flash family, ML-1 NAND flash family, and ML-2 NAND flash family, these pins are not bonded internally; so they can be left open. Similarly, the packaging type does not affect this condition; the same procedure can be followed for both TSOP1 and BGA packages.