SB_IO #(
        .PIN_TYPE(6'b 1010_01),
        .PULLUP(1'b 0)
    ) flash_io_buf [3:0] (
        .PACKAGE_PIN({flash_io3, flash_io2, flash_io1, flash_io0}),
        .OUTPUT_ENABLE({flash_io3_oe, flash_io2_oe, flash_io1_oe, flash_io0_oe}),
        .D_OUT_0({flash_io3_do, flash_io2_do, flash_io1_do, flash_io0_do}),
        .D_IN_0({flash_io3_di, flash_io2_di, flash_io1_di, flash_io0_di})
    );