at45db021d-ssh-sl955 ATMEL Corporation, at45db021d-ssh-sl955 Datasheet - Page 23

• Manufacturer Part Number: at45db021d-ssh-sl955
• Description: 2-megabit 2.7-volt Minimum Dataflash
• Manufacturer: ATMEL Corporation

AT45DB021D
data in the buffer. If bit 6 is a 1, then at least one bit of the data in the main memory page does
not match the data in the buffer.
Bit 1 in the Status Register is used to provide information to the user whether or not the sector
protection has been enabled or disabled, either by software-controlled method or hardware-con-
trolled method. A logic 1 indicates that sector protection has been enabled and logic 0 indicates
that sector protection has been disabled.
Bit 0 in the Status Register indicates whether the page size of the main memory array is config-
ured for “power of 2” binary page size (256 bytes) or the DataFlash standard page size
(264 bytes). If bit 0 is a 1, then the page size is set to 256 bytes. If bit 0 is a 0, then the page size
is set to 264 bytes.
The device density is indicated using bits 5, 4, 3, and 2 of the status register. For the
AT45DB021D, the four bits are 0101 The decimal value of these four binary bits does not equate
to the device density; the four bits represent a combinational code relating to differing densities
of DataFlash devices. The device density is not the same as the density code indicated in the
JEDEC device ID information. The device density is provided only for backward compatibility.
Table 11-1.
Status Register Format
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RDY/BUSY
COMP
0
1
0
1
PROTECT
PAGE SIZE
23
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