N25Q128 Numonyx, N25Q128 Datasheet - Page 34

• Manufacturer Part Number: N25Q128
• Description: 128-mbit 3 V, Multiple I/o, 4-kbyte Subsector Erase On Boot Sectors, Xip Enabled, Serial Flash Memory With 108 Mhz Spi Bus Interface
• Manufacturer: Numonyx

6.1
6.1.1
6.1.2
6.1.3
6.1.4
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Legacy SPI Status Register
The Status Register contains a number of status and control bits that can be read or set by
specific instructions: Read Status Register (RDSR) and Write Status Register (WRSR). This
is available in all the 3 protocols (Extended SPI, DIO-SPI, and QIO-SPI).
Table 2.
WIP bit
The Write In Progress (WIP) bit set to 1 indicates that the memory is busy with a Write
Status Register, Program or Erase cycle. 0 indicates no cycle is in progress.
WEL bit
The Write Enable Latch (WEL) bit set to 1 indicates that the internal Write Enable Latch is
set. When set to 0 the internal Write Enable Latch is reset and no Write Status Register,
Program or Erase instruction is accepted.
BP3, BP2, BP1, BP0 bits
The Block Protect (BP3, BP2, BP1, BP0) bits are non-volatile. They define the size of the
area to be software protected against Program and Erase instructions. These bits are
written with the Write Status Register (WRSR) instruction. When one or more of the Block
Protect (BP3, BP2, BP1, BP0) bits is set to 1, the relevant memory area, as defined in
9.: Protected area sizes (TB bit = 0)
becomes protected against all program and erase instructions. The Block Protect (BP3,
BP2, BP1, BP0) bits can be written provided that the Hardware Protected mode has not
been set. The Bulk Erase (BE) instruction is executed if, and only if, all Block Protect (BP3,
BP2, BP1, BP0) bits are 0.
TB bit
The Top/Bottom (TB) bit is non-volatile. It can be set and reset with the Write Status Register
(WRSR) instruction provided that the Write Enable (WREN) instruction has been issued.
Status register write protect
SRWD
b7
Status register format
BP3
Top/bottom bit
TB
and
Table 10.: Protected area sizes (TB bit =
BP2
Block protect bits
BP1
Write enable latch bit
BP0
WEL
Write in progress bit
1),
WIP
b0
Table