TC58FVT641 datasheet(13/53 Pages) TOSHIBA

13 / 53 page

TC58FVT641/B641FT/XB-70,-10

2001-09-06

13/53

Hidden ROM Area

The TC58FVT641/B641 features a 64-Kbyte hidden ROM area which is separate from the memory cells. The

area consists of one block. Data Read, Write and Protect can be performed on this block. Because Protect cannot

be released, once the block is protected, data in the block cannot be overwritten.

The hidden ROM area is located in the address space indicated in the HIDDEN ROM AREA ADDRESS

TABLE. To access the Hidden ROM area, input a Hidden ROM Mode Entry command. The device now enters

Hidden ROM Mode, allowing Read, Write, Erase and Block Protect to be executed. Write and Erase operations

are the same as auto operations except that the device is in Hidden ROM Mode. However, regarding write

operation, Accelaration mode can not be performed during Hidden ROM Mode. To protect the hidden ROM area,

use the block protection function. The operation of Block Protect here is the same as a normal Block Protect

except that VIH rather than VID is input to RESET . Once the block has been protected, protection cannot be

released, even using the temporary block unprotection function. Use Block Protect carefully. Note that in

Hidden ROM Mode, simultaneous operation cannot be performed. Therefore, do not attempt to access areas

other than the hidden ROM area.

To exit Hidden ROM Mode, use the Hidden ROM Mode Exit command. This will return the device to Read

Mode.

HIDDEN ROM AREA ADDRESS TABLE

BYTE MODE

WORD MODE

TYPE

BOOT BLOCK

ARCHITECTURE

ADDRESS RANGE

SIZE

ADDRESS RANGE

SIZE

TC58FVT641

TOP BOOT BLOCK

7F0000H~7FFFFFH

64 Kbytes

3F8000H~3FFFFFH

32 Kwords

TC58FVB641

BOTTOM BOOT BLOCK

000000H~00FFFFH

64 Kbytes

000000H~007FFFH

32 Kwords

TC58FVT641 Scheda tecnica(PDF) 13 Page - Toshiba Semiconductor