S29GL256N10TFI023 ETC, S29GL256N10TFI023 Datasheet - Page 70

• Manufacturer Part Number: S29GL256N10TFI023
• Description: MirrorBit Flash Family
• Manufacturer: ETC

70
Non-Volatile Sector Protection Command Set Definitions
Global Volatile Sector Protection Freeze Command Set
The Password Protection Command Set Exit command must be issued after
the execution of the commands listed previously to reset the device to read
mode. Otherwise the device will hang.
Note that issuing the Password Protection Command Set Exit command re-
enables reads and writes for the main memory.
The Non-Volatile Sector Protection Command Set permits the user to program the
Persistent Protection Bits (PPB bits), erase all of the Persistent Protection Bits
(PPB bits), and read the logic state of the Persistent Protection Bits (PPB bits).
The Non-Volatile Sector Protection Command Set Entry command se-
quence must be issued prior to any of the commands listed following to enable
proper command execution.
Note that issuing the Non-Volatile Sector Protection Command Set Entry
command disables reads and writes for the main memory.
The PPB Program command is used to program, or set, a given PPB bit. Each PPB
bit is individually programmed (but is bulk erased with the other PPB bits). The
specific sector address (A24-A16 for S29GL512N, A23-A16 for S29GL256N, A22-
A16 for S29GL128N) is written at the same time as the program command. If the
PPB Lock Bit is set to the “freeze state”, the PPB Program command will not exe-
cute and the command will time-out without programming the PPB bit.
The All PPB Erase command is used to erase all PPB bits in bulk. There is no
means for individually erasing a specific PPB bit. Unlike the PPB program, no spe-
cific sector address is required. However, when the All PPB Erase command is
issued, all Sector PPB bits are erased in parallel. If the PPB Lock Bit is set to
“freeze state”, the ALL PPB Erase command will not execute and the command
will time-out without erasing the PPB bits.
The device will preprogram all PPB bits prior to erasing when issuing the All PPB
Erase command. Also note that the total number of PPB program/erase cycles has
the same endurance as the flash memory array.
The programming state of the PPB for a given sector can be verified by writing a
PPB Status Read Command to the device. This requires an initial access time
latency.
The Non-Volatile Sector Protection Command Set Exit command must be
issued after the execution of the commands listed previously to reset the device
to read mode.
Note that issuing the Non-Volatile Sector Protection Command Set Exit
command re-enables reads and writes for the main memory.
The Global Volatile Sector Protection Freeze Command Set permits the user to set
the PPB Lock Bit and reading the logic state of the PPB Lock Bit.
The Global Volatile Sector Protection Freeze Command Set Entry com-
mand sequence must be issued prior to any of the commands listed following to
enable proper command execution.
PPB Program Command
All PPB Erase Command
PPB Status Read Command
S29GLxxxN MirrorBitTM Flash Family
A d v a n c e
I n f o r m a t i o n
27631A4 May 13, 2004