28F004/400B3, 28F008/800B3, 28F016/160B3, 28F320B3, 28F640B3
When the device is in read array mode, four control signals control data output:
• WE# must be logic high (VIH)
• CE# must be logic low (VIL)
• OE# must be logic low (VIL)
• RP# must be logic high (VIH)
In addition, the address of the desired location must be applied to the address pins. If the device is
not in read array mode, as would be the case after a program or erase operation, the Read Array
command (FFH) must be written to the CUI before array reads can take place.
Table 4. Command Codes and Descriptions
Unassigned commands that should not be used. Intel reserves the right to redefine these
codes for future functions.
Program / Erase
Program / Erase
Places the device in read array mode, such that array data will be output on the data pins.
This is a two-cycle command. The first cycle prepares the CUI for a program operation. The
second cycle latches addresses and data information and initiates the WSM to execute the
Program algorithm. The flash outputs status register data when CE# or OE# is toggled. A Read
Array command is required after programming to read array data. See Section 3.2.4.
(See 40H/Program Set-Up)
Prepares the CUI for the Erase Confirm command. If the next command is not an Erase
Confirm command, then the CUI will (a) set both SR.4 and SR.5 of the status register to a “1,”
(b) place the device into the read status register mode, and (c) wait for another command. See
If the previous command was an Erase Set-Up command, then the CUI will close the address
and data latches, and begin erasing the block indicated on the address pins. During erase, the
device will only respond to the Read Status Register and Erase Suspend commands. The
device will output status register data when CE# or OE# is toggled.
If a program or erase operation was previously suspended, this command will resume that
Issuing this command will begin to suspend the currently executing program/erase operation.
The status register will indicate when the operation has been successfully suspended by
setting either the program suspend (SR.2) or erase suspend (SR.6) and the WSM status bit
(SR.7) to a “1” (ready). The WSM will continue to idle in the SUSPEND state, regardless of the
state of all input control pins except RP#, which will immediately shut down the WSM and the
remainder of the chip if it is driven to VIL. See Section 184.108.40.206 and Section 220.127.116.11.
This command places the device into read status register mode. Reading the device will output
the contents of the status register, regardless of the address presented to the device. The
device automatically enters this mode after a program or erase operation has been initiated.
See Section 3.2.3.
The WSM can set the block lock status (SR.1) , VPP status (SR.3), program status (SR.4), and
erase status (SR.5) bits in the status register to “1,” but it cannot clear them to “0.” Issuing this
command clears those bits to “0.”
Puts the device into the intelligent identifier read mode, so that reading the device will output
the manufacturer and device codes (A0 = 0 for manufacturer, A0 = 1 for device, all other
address inputs must be 0). See Section Section 3.2.2.
NOTE: See Appendix A for mode transition information.