Rainbow Electronics AT45DQ321 - Manual (Page 33)

33 AT45DQ321 [ADVANCE DATASHEET]
DS-45DQ321-031–DFLASH–12/2012
Table 9-2. Status Register Format – Byte 2
Note: 1. R = Readable only
9.4.1 RDY/BUSY Bit
The RDY/BUSY bit is used to determine whether or not an internal operation, such as a program or erase, is in progress.
To poll the RDY/BUSY bit to detect the completion of an internally timed operation, new Status Register data must be
continually clocked out of the device until the state of the RDY/BUSY bit changes from a Logic 0 to a Logic 1.
9.4.2 COMP Bit
The result of the most recent Main Memory Page to Buffer Compare operation is indicated using the COMP bit. If the
COMP bit is a Logic 1, then at least one bit of the data in the Main Memory Page does not match the data in the buffer.
9.4.3 DENSITY Bits
The device density is indicated using the DENSITY bits. For the AT45DQ321, the four bit binary value is 1101. The
decimal value of these four binary bits does not actually equate to the device density; the four bits represent a
combinational code relating to differing densities of DataFlash devices. The DENSITY bits are not the same as the
density code indicated in the JEDEC Device ID information. The DENSITY bits are provided only for backward
compatibility to older generation DataFlash devices.
9.4.4 PROTECT Bit
The PROTECT bit provides information to the user on whether or not the sector protection has been enabled or disabled,
either by the software-controlled method or the hardware-controlled method.
9.4.5 PAGE SIZE Bit
The PAGE SIZE bit indicates whether the buffer size and the page size of the main memory array is configured for the
“power of 2” binary page size (512 bytes) or the standard DataFlash page size (528 bytes).
Bit Name Type (1) Description
7 RDY/BUSY Ready/Busy Status R
0 Device is busy with an internal operation.
1 Device is ready.
6 RES Reserved for Future Use R 0 Reserved for future use.
5 EPE Erase/Program Error R
0 Erase or program operation was successful.
1 Erase or program error detected.
4 RES Reserved for Future Use R 0 Reserved for future use.
3 SLE Sector Lockdown Enabled R
0 Sector Lockdown command is disabled.
1 Sector Lockdown command is enabled.
2 PS2
Program Suspend Status
(Buffer 2)
R
0 No program operation has been suspended while using Buffer 2.
1 A sector is program suspended while using Buffer 2.
1 PS1
Program Suspend Status
(Buffer 1)
R
0 No program operation has been suspended while using Buffer 1.
1 A sector is program suspended while using Buffer 1.
0 ES Erase Suspend R
0 No sectors are erase suspended.
1 A sector is erase suspended.