AT49BV802DT Ver la hoja de datos (PDF) - Atmel Corporation

Número de pieza

componentes Descripción

Fabricante

AT49BV802DT

8-megabit (512K x 16/1M x 8) 3-volt Only Flash Memory

Atmel Corporation 

4.9 Program Suspend/Program Resume

The Program Suspend command allows the system to interrupt a programming operation and

then read data from a different byte/word within the memory. After the Program Suspend com-

mand is given, the device requires a maximum of 20 µs to suspend the programming operation.

After the programming operation has been suspended, the system can then read data from any

other byte/word that is not contained in the sector in which the programming operation was sus-

pended. An address is not required during the program suspend operation. To resume the

programming operation, the system must write the Program Resume command. The program

suspend and resume are one-bus cycle commands. The command sequence for the erase sus-

pend and program suspend are the same, and the command sequence for the erase resume

and program resume are the same.

4.10

Product Identification

The product identification mode identifies the device and manufacturer as Atmel. It may be

accessed by hardware or software operation. The hardware operation mode can be used by an

external programmer to identify the correct programming algorithm for the Atmel product.

For details, see “Operating Modes” on page 17 (for hardware operation) or “Software Product

Identification Entry/Exit” sections on page 24. The manufacturer and device codes are the same

for both modes.

4.11

128-bit Protection Register

The AT49BV802D(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 blocks. The two blocks are

designated as block A and block B. The data in block A is non-changeable and is programmed

at the factory with a unique number. The data in block B is programmed by the user and can be

locked out such that data in the block cannot be reprogrammed. To program block B in the pro-

tection register, the four-bus cycle Program Protection Register command must be used as

shown in the “Command Definition Table” on page 13. To lock out block B, the four-bus cycle

Lock Protection Register command must be used as shown in the “Command Definition Table”.

Data bit D1 must be zero during the fourth bus cycle. All other data bits during the fourth bus

cycle are don’t cares. To determine whether block B is locked out, the status of Block B Protec-

tion command is given. If data bit D1 is zero, block B is locked. If data bit D1 is one, block B can

be reprogrammed. Please see the “Protection Register Addressing Table” on page 14 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 protection

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

the Product ID Exit command must be given prior to performing any other operation.

4.12 RDY/BUSY

An open-drain READY/BUSY output pin provides another method of detecting the end of a pro-

gram or erase operation. RDY/BUSY is actively pulled low during the internal program and erase

cycles and is released at the completion of the cycle. The open-drain connection allows for OR-

tying of several devices to the same RDY/BUSY line. Please see “Status Bit Table” on page 12

for more details.

8 AT49BV802D(T)

3626A–FLASH–2/07

Share Link: