mx25l12845e Macronix International Co., mx25l12845e Datasheet - Page 31

• Manufacturer Part Number: mx25l12845e
• Description: Mx25l12845e High Performance Serial Flash Specification Preliminary
• Manufacturer: Macronix International Co.

P/N: PM1428
Block Lock Flow
(29) Single Block Lock/Unlock Protection (SBLK/SBULK)
These instructions are only effective after WPSEL was executed. The SBLK instruction is for write protection a spec-
ified block(or sector) of memory, using A23-A16 or (A23-A12) address bits to assign a 64Kbyte block (or 4K bytes
sector) to be protected as read only. The SBULK instruction will cancel the block (or sector) write protection state.
This feature allows user to stop protecting the entire block (or sector) through the chip unprotect command (GBULK).
The WREN (Write Enable) instruction is required before issuing SBLK/SBULK instruction.
The sequence of issuing SBLK/SBULK instruction is: CS# goes low → send SBLK/SBULK (36h/39h) instruction →
send 3 address bytes assign one block (or sector) to be protected on SI pin → CS# goes high. (see Figure 41)
The CS# must go high exactly at the byte boundary, otherwise the instruction will be rejected and not be executed.
SBLK/SBULK instruction function flow is as follows:
RDSCUR(2Bh) command
( 36h + 24bit address )
( 3Ch + 24bit address )
Block lock successfully
RDBLOCK command
Block lock completed
Lock another block?
WREN command
SBLK command
RDSR command
WPSEL=1?
Data = FFh ?
WIP=0?
Start
Yes
No
Yes
Yes
No
No
No
Yes
31
WPSEL command
Block lock fail
MX25L12845E
REV. 0.06, MAR. 05, 2009