TH50VSF2582 Datasheet, PDF (25/50 Pages) Toshiba Semiconductor – SRAM AND FLASH MEMORY MIXED MULTI-CHIP PACKAGE

Block Protection
TH50VSF2582/2583AASB
Block Protection is a function to disable write and erase in block units.
Applying VID to RESET and inputting the Block Protect command performs block protection. The first cycle of
the command sequence is the Setup command. In the second cycle, the Block Protect command is input, in
which a block address and A1 = VIH and A0 = A6 = VIL are input. At this time, the device writes to the block
protector circuit, Until write is complete, there must be a wait of tPPLH but the device need not be controlled
during this time. In the third cycle, the Verify Block Protect command is input. This command verifies write to
the block protector circuit. Read is performed in the fourth cycle. If the protection operation is complete, 01H is
output. If other than 01H is output, write is not complete; thus, input the Block Protect command again.
Canceling VID to RESET exits this mode.
Temporary Block Unprotection
The TC58VSF2582/2583AASB has a temporary block unprotection feature which disables block protection for
all protected blocks. Unprotection is enabled by applying VID to the RESET pin. Now Write and Erase
operations can be performed on all blocks except the boot blocks which have been protected by the Boot Block
Protect operation. The device returns to its previous state when VID is removed from the RESET pin. That is,
previously protected blocks will be protected again.
Verify Block Protect
The Verify Block Protect command is used to ascertain whether a block is protected or unprotected. This mode
is set by setting A0, A6 and the block address A19~A12 to VIL and setting A1 to VIH. This command should be
input before a Read operation is performed. 0001H is output if the block is protected and 0000H is output if the
block is unprotected. In Byte Mode DQ8 to DQ15 are in High-Impedance state. Block protection verification can
also be carried out using a software command.
Boot Block Protection
Boot block protection temporarily protects certain boot blocks using a method different from ordinary block
protection. Neither VID nor a command sequence is required. Protection is performed simply by inputting VIL
on WP/ACC . The target blocks are the two pairs of boot blocks. The top boot blocks are BA69 and BA70; the
bottom boot blocks are BA0 and BA1. Inputting VIH on WP/ACC releases the mode. From now on, if it is
necessary to protect these blocks, the ordinary Block Protection Mode must be used.
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