8

AT25F2048

2455I–SFLSH–5/07

READ PRODUCT ID (RDID): The RDID instruction allows the user to read the manufac-

turer and product ID of the device. The first byte after the instruction will be the

manufacturer code (1FH = ATMEL), followed by the device code, 63H.

WRITE STATUS REGISTER (WRSR): The WRSR instruction allows the user to select

one of four levels of protection for the AT25F2048. The AT25F2048 is divided into four

sectors where the top quarter (1/4), top half (1/2), or all of the memory sectors can be

protected (locked out) from write. Any of the locked-out sectors will therefore be read

only. The locked-out sector and the corresponding status register control bits are shown

in Table 7.

The three bits, BP0, BP1, and WPEN, are nonvolatile cells that have the same proper-

Table 6. Read Status Register Bit Definition

Bit

Definition

Bit 0 (RDY)

Bit 0 = 0 (RDY) indicates the device is READY. Bit 0 = 1 indicates the

write cycle is in progress.

Bit 1 (WEN)

Bit 1 = 0 indicates the device is not WRITE ENABLED. Bit 1 = 1 indicates

the device is WRITE ENABLED.

Bit 2 (BP0)

See Table 7.

Bit 3 (BP1)

See Table 7.

Bits 4-6 are 0s when device is not in an internal write cycle.

Bit 7 (WPEN)

See Table 8.

Bits 0-7 are 1s during an internal write cycle.

Table 7. Block Write Protect Bits

Level

Status Register Bits

AT25F2048

BP1

BP0

Array Addresses

Locked Out

Locked-out

Sector(s)

0

0

0

None

None

1(1/4)

0

1

030000 - 03FFFF

Sector 4

2(1/2)

1

0

020000 - 03FFFF

Sector 3, 4

3(All)

1

1

000000 - 03FFFF

All sectors

(1 - 4)