Register definition:
Status Register:
  Bit        Name                            Settings:    
   7         Status Register Write Enable    0: Enabled(Default), 1: Disabled
   5         Top/Bottom                      0: Top(Default), 1: Bottom
6, 4-2       BP[3:0]                         See Protected Area table

Nonvolatile Configuration Register:
  Bit        Name                            Settings:    
 15:12       Number of dummy clocks          0000=1111=Default, 0001=1, 0010=2 ...
 11:9        XIP mode at power-on reset      
  8:6        Output driver strength          
   5         Double Transfer rate protocol   1=Disabled(Default), 0=Enabled
   4         Reset/hold                      1=Enabled(Default), 0=Disabled
   3         Quad I/O                        1=Disabled(Default), 0=Enabled
   2         Dual I/O                        1=Disabled(Default), 0=Enabled
   1         Reserved                        1 
   0         Reserved                        1 