Document Number: 001-98285 Rev. *R
Page 11 of 108
S29GL01GS/S29GL512S
S29GL256S/S29GL128S
2.7
Sector Protection Control
2.7.1
Lock Register ASO
The Lock register ASO contains a single word of OTP memory. When the ASO is entered the Lock Register appears at all word
locations in the device address space. See
for ASO Entry timing requirements. However, it is
recommended to read or program the Lock Register only at location 0 of the device address space for future compatibility.
2.7.2
Persistent Protection Bits (PPB) ASO
The PPB ASO contains one bit of a Flash Memory Array for each Sector in the device. When the PPB ASO is entered, the PPB bit
for a sector appears in the Least Significant Bit (LSB) of each address in the sector. See
for ASO Entry
timing requirements. Reading any address in a sector displays data where the LSB indicates the non-volatile protection status for
that sector. However, it is recommended to read or program the PPB only at address 0 of the sector for future compatibility. If the bit
is 0 the sector is protected against programming and erase operations. If the bit is 1 the sector is not protected by the PPB. The
sector may be protected by other features of ASP.
2.7.3
PPB LOCK ASO
The PPB Lock ASO contains a single bit of volatile memory. The bit controls whether the bits in the PPB ASO may be programmed
or erased. If the bit is 0 the PPB ASO is protected against programming and erase operations. If the bit is 1 the PPB ASO is not
protected. When the PPB Lock ASO is entered the PPB Lock bit appears in the Least Significant Bit (LSB) of each address in the
device address space. See
for ASO Entry timing requirements. However, it is recommended to read or
program the PPB Lock only at address 0 of the device for future compatibility.
2.7.4
Password ASO
The Password ASO contains four words of OTP memory. When the ASO is entered the Password appears starting at address 0 in
the device address space. See
for ASO Entry timing requirements. All locations above the forth word are
undefined.
2.7.5
Dynamic Protection Bits (DYB) ASO
The DYB ASO contains one bit of a volatile memory array for each Sector in the device. When the DYB ASO is entered, the DYB bit
for a sector appears in the Least Significant Bit (LSB) of each address in the sector. See
for ASO Entry
timing requirements. Reading any address in a sector displays data where the LSB indicates the non-volatile protection status for
that sector. However, it is recommended to read, set, or clear the DYB only at address 0 of the sector for future compatibility. If the
bit is 0 the sector is protected against programming and erase operations. If the bit is 1 the sector is not protected by the DYB. The
sector may be protected by other features of ASP.
2.8
ECC Status ASO
The system can access the ECC Status ASO by issuing the ECC Status entry command sequence during Read Mode. The ECC
Status ASO provides the status of a Single Bit Error correction when reading the selected page.
describes the ECC function in more detail. See
for ASO Entry timing requirements.
The ECC Status ASO allows the following activities:
Read ECC Status for the selected page.
ASO Exit.
2.8.1
ECC Status
The contents of the ECC Status ASO indicates, for the selected ECC page, whether ECC protection has corrected an error in the
eight-bit error correction code or the 16 Words of data in the ECC page. The address specified in the ECC Status Read Command,
provided in
selects the ECC Page.
