Rainbow Electronics AT25F2048 User Manual
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AT25F2048
2455D–SEEPR–7/04
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 4.
The three bits, BP0, BP1, and WPEN, are nonvolatile cells that have the same proper-
ties and functions as the regular memory cells (e.g., WREN, t
WC
, RDSR).
Table 3. 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)
Bit 3 (BP1)
Bits 4-6 are 0s when device is not in an internal write cycle.
Bit 7 (WPEN)
Bits 0-7 are 1s during an internal write cycle.
Table 4. 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)