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AT49BV160D

16-megabit (1M x 16) 3-volt Only Flash Memory

Atmel Corporation 

AT49BV160D(T)

4.12

128-bit Protection Register

The AT49BV160D(T) contains a 128-bit register that can be used for security purposes in sys-

tem design. The protection register is divided into two 64-bit sectors. The two sectors are

designated as sector A and sector B. The data in sector A is non-changeable and is pro-

grammed at the factory with a unique number. The data in sector B is programmed by the user

and can be locked out such that data in the sector cannot be reprogrammed. To program sector

B in the protection register, the two-bus cycle Program Protection Register command must be

used as shown in the “Command Definition Table” on page 15. To lock out sector B, the two-bus

cycle Lock Protection Register command must be used as shown in the “Command Definition

Table” . Data bit D1 must be zero during the second bus cycle. All other data bits during the sec-

ond bus cycle are don’t cares. To determine whether sector B is locked out, use the status of

sector B protection command. If data bit D1 is zero, sector B is locked. If data bit D1 is one, sec-

tor B can be reprogrammed. Please see the “Protection Register Addressing Table” on page 16

for the address locations in the protection register. To read the protection register, the Product

ID Entry command is given followed by a normal read operation from an address within the pro-

tection register. After determining whether sector B is protected or not, or reading the protection

register, the Read command must be given to return to the read mode.

4.13

Common Flash Interface (CFI)

CFI is a published, standardized data structure that may be read from a flash device. CFI allows

system software to query the installed device to determine the configurations, various electrical

and timing parameters and functions supported by the device. CFI is used to allow the system to

learn how to interface to the flash device most optimally. The two primary benefits of using CFI

are ease of upgrading and second source availability. The command to enter the CFI Query

mode is a one-bus cycle command which requires writing data 98h to any address. The CFI

Query command can be written when the device is ready to read data or can also be written

when the part is in the product ID mode. Once in the CFI Query mode, the system can read CFI

data at the addresses given in “Common Flash Interface Definition Table” on page 24. To return

to the read mode, issue the Read command.

4.14

Hardware Data Protection

The Hardware Data Protection feature protects against inadvertent programs to the

AT49BV160D(T) in the following ways: (a) VCC sense: if VCC is below 1.8V (typical), the program

function is inhibited. (b) Program inhibit: holding any one of OE low, CE high or WE high inhibits

program cycles. (c) Program inhibit: VPP is less than VILPP.

4.15

Input Levels

While operating with a 2.65V to 3.6V power supply, the address inputs and control inputs (OE,

CE and WE) may be driven from 0 to 5.5V without adversely affecting the operation of the

device. The I/O lines can only be driven from 0 to VCCQ + 0.6V.

4.16

Output Levels

For the AT49BV160D(T), output high levels (VOH) are equal to VCCQ - 0.1V (not VCC). For

2.65V -3.6V output levels, VCCQ must be tied to VCC.

9

3591C–FLASH–6/06

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