28F1602C3, 28F3204C3
E
12
PRODUCT PREVIEW
read cycles from addresses shown in Table 4
retrieve the specified information. To return to read
array mode, write the Read Array command (FFH).
The Read Configuration mode outputs three types
of information: the manufacturer/device identifier,
the block locking status, and the protection register.
The device is switched to this mode by writing the
Read Configuration command (90H). Once in this
mode, read cycles from addresses shown in
Table 4 retrieve the specified information. To return
to read array mode, write the Read Array command
(FFH).
Table 4. Read Configuration Table
Item
Address
Data
Manufacturer Code (x16)
00000
0089
Device ID (See Appendix G)
00001
ID
Block Lock Configuration
2
XX002
(1)
LOCK
Block Is Unlocked
DQ
0
= 0
Block Is Locked
DQ
0
= 1
Block Is Locked-Down
DQ
1
= 1
Protection Register Lock
3
80
PR-LK
Protection Register (x16)
81-88
PR
NOTES:
1.
“XX” specifies the block address of lock configuration
being read.
See Section 6.4 for valid lock status outputs.
See Section 7.0 for protection register information.
Other locations within the configuration address space
are reserved by Intel for future use.
2.
3.
4.
5.3
Read Status Register
The status register indicates the status of device
operations,
and
the
operation. The Read Status Register (70H)
command causes subsequent reads to output data
from the status register until another command is
issued. To return to reading from the array, issue a
Read Array (FFH) command.
success/failure
of
that
The status register bits are output on DQ
0
–DQ
7
.
The upper byte, DQ
8
–DQ
15
, outputs 00H during a
Read Status Register command.
The contents of the status register are latched on
the falling edge of F-OE# or F-CE#, whichever
occurs last. This prevents possible bus errors which
might occur if status register contents change while
being read. F-CE# or F-OE# must be toggled with
each subsequent status read, or the status register
will not indicate completion of a program or erase
operation.
When the WSM is active, SR.7 will indicate the
status of the WSM; the remaining bits in the status
register indicate whether the WSM was successful
in performing the desired operation (see Table 6).
5.3.1
CLEARING THE STATUS REGISTER
The WSM sets status bits 1 through 7 to “1,” and
clears bits 2, 6 and 7 to “0,” but cannot clear status
bits 1 or 3 through 5 to “0.” Because bits 1, 3, 4 and
5 indicate various error conditions, these bits can
only be cleared through the use of the Clear Status
Register (50H) command. By allowing the system
software to control the resetting of these bits,
several operations may be performed (such as
cumulatively programming several addresses or
erasing multiple blocks in sequence) before reading
the status register to determine if an error occurred
during that series. Clear the status register before
beginning another command or sequence. Note
that the Read Array command must be issued
before data can be read from the memory array.
Resetting the device also clears the status register.
5.4
Read Query
The read query mode outputs Common Flash
Interface (CFI) data when the device is read. This
can be accessed by writing the Read Query
Command (98H). The CFI data structure contains
information such as block size, density, command
set and electrical specifications. Once in this mode,
read cycles from addresses shown in Appendix B
retrieve the specified information. To return to read
array mode, write the Read Array command (FFH).
5.5
Program Mode
Programming is executed using a two
-
write
sequence. The Program Setup command (40H) is
written to the CUI followed by a second write which
specifies the address and data to be programmed.
The WSM will execute a sequence of internally
timed events to program desired bits of the
addressed location, then verify the bits are
sufficiently programmed. Programming the memory
results in specific bits within an address location