S29GL01GS Datasheet, PDF (35/104 Pages) SPANSION – GL-S MirrorBit® Eclipse™ Flash Non-Volatile Memory Family

Data Sheet
5.3.6 ASO Entry and Exit
5.3.6.1
5.3.6.2
ID-CFI ASO
The system can access the ID-CFI ASO by issuing the ID-CFI Entry command sequence during Read Mode.
This entry command uses the Sector Address (SA) in the command to determine which sector will be overlaid
and which sector's protection state is reported in word location 2h. See the detail description Table 6.2
on page 60.
The ID-CFI ASO allows the following activities:
 Read ID-CFI ASO, using the same SA as used in the entry command.
 Read Sector Protection State at Sector Address (SA) + 2h. Location 2h provides volatile information on the
current state of sector protection for the sector addressed. Bit 0 of the word at location 2h shows the logical
NAND of the PPB and DYB bits related to the addressed sector such that if the sector is protected by either
the PPB=0 or the DYB=0 bit for that sector the state shown is protected. (1= Sector protected, 0= Sector
unprotected). This protection state is shown only for the SA selected when entering ID-CFI ASO. Reading
other SA provides undefined data. To read a different SA protection state ASO exit command must be used
and then enter ID-CFI ASO again with the new SA.
 ASO Exit.
The following is a C source code example of using the CFI Entry and Exit functions. Refer to the Spansion
Low Level Driver User's Guide (available on www.spansion.com) for general information on Spansion flash
memory software development guidelines.
/* Example: CFI Entry command */
*( (UINT16 *)base_addr + 0x55 ) = 0x0098; /* write CFI entry command */
/* Example: CFI Exit command */
*( (UINT16 *)base_addr + 0x000 ) = 0x00F0; /* write cfi exit command */
Status Register ASO
When the Status Register read command is issued, the current status is captured by the register and the
ASO is entered. The first read access in the Status Register ASO exits the ASO and returns to the address
space map in use when the Status Register read command was issued. No other command should be sent
before reading the status to exit the Status register ASO.
5.3.6.3
Secure Silicon Region ASO
The system can access the Secure Silicon Region by issuing the Secure Silicon Region Entry command
sequence during Read Mode. This entry command uses the Sector Address (SA) in the command to
determine which sector will be overlaid.
The Secure Silicon Region ASO allows the following activities:
 Read Secure Silicon Regions, using the same SA as used in the entry command.
 Program the customer Secure Silicon Region using the Word or Write Buffer Programming commands.
 ASO Exit using legacy Secure Silicon Exit command for backward software compatibility.
 ASO Exit using the common exit command for all ASO - alternative for a consistent exit method.
March 16, 2012 S29GL_128S_01GS_00_06
GL-S MirrorBit^® Family
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