s29gl01gp Meet Spansion Inc., s29gl01gp Datasheet - Page 51

• Manufacturer Part Number: s29gl01gp
• Description: 3.0 Volt-only Page Mode Flash Memory Featuring 90 Nm Mirrorbit Process Technology
• Manufacturer: Meet Spansion Inc.

10.2
10.3
June 11, 2008 S29GL-P_00_A11
Customer Lockable Secured Silicon Sector
Secured Silicon Sector Entry/Exit Command Sequences
The Customer Lockable Secured Silicon Sector is always shipped unprotected (DQ7 set to “0”), allowing
customers to utilize that sector in any manner they choose. If the security feature is not required, the Secured
Silicon Sector can be treated as an additional Flash memory space.
Please note the following:
The system can access the Secured Silicon Sector region by issuing the three-cycle Enter Secured Silicon
Sector command sequence. The device continues to access the Secured Silicon Sector region until the
system issues the four-cycle Exit Secured Silicon Sector command sequence.
See
Table 12.1 on page 69
sequences.
The Secured Silicon Sector Entry Command allows the following commands to be executed
After the system has written the Enter Secured Silicon Sector command sequence, it may read the Secured
Silicon Sector by using the addresses normally occupied by sector SA0 within the memory array. This mode
of operation continues until the system issues the Exit Secured Silicon Sector command sequence, or until
power is removed from the device.
Software Functions and Sample Code
The following are C functions and source code examples of using the Secured Silicon Sector Entry, Program,
and exit commands. Refer to the Spansion Low Level Driver User’s Guide (available soon on
www.spansion.com) for general information on Spansion Flash memory software development guidelines.
Note
Base = Base Address.
Once the Secured Silicon Sector area is protected, the Secured Silicon Sector Indicator Bit is permanently
set to “0.”
The Secured Silicon Sector can be read any number of times, but can be programmed and locked only
once. The Secured Silicon Sector lock must be used with caution as once locked, there is no procedure
available for unlocking the Secured Silicon Sector area and none of the bits in the Secured Silicon Sector
memory space can be modified in any way.
The accelerated programming (ACC) and unlock bypass functions are not available when the Secured
Silicon Sector is enabled.
Once the Secured Silicon Sector is locked and verified, the system must write the Exit Secured Silicon
Sector Region command sequence which return the device to the memory array at sector 0.
Read customer and factory Secured Silicon areas
Program the customer Secured Silicon Sector
/* Example: SecSi Sector Entry Command */
Command Definitions on page 68
*( (UINT16 *)base_addr + 0x555 ) = 0x00AA;
*( (UINT16 *)base_addr + 0x2AA ) = 0x0055;
*( (UINT16 *)base_addr + 0x555 ) = 0x0088;
Unlock Cycle 1
Unlock Cycle 2
Entry Cycle
Cycle
through
D a t a
S29GL-P MirrorBit
Table 12.4 on page 72
Table 10.2 Secured Silicon Sector Entry
(LLD Function = lld_SecSiSectorEntryCmd)
S h e e t
Operation
[Secured Silicon Sector Command Table, Appendix
Write
Write
Write
®
Flash Family
/* write unlock cycle 1
/* write unlock cycle 2
/* write Secsi Sector Entry Cmd
for address and data requirements for both command
Byte Address
Base + AAAh
Base + AAAh
Base + 555h
Word Address
Base + 2AAh
Base + 555h
Base + 555h
*/
*/
*/
00AAh
0055h
0088h
Data
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