The AVR specific public JTAG instruction to directly load the Flash data page via the JTAG port. The 2048-bit Virtual Flash Page Load Register is selected as data register. This is a virtual scan chain with length equal to the number of bits in one Flash page. Internally the Shift Register is 8-bit. Unlike most JTAG instructions, the Update-DR state is not used to transfer data from the Shift Register. The data are automatically transferred to the Flash page buffer byte by byte in the Shift-DR state by an internal state machine. This is the only active state: