After the final buffer data is given, a Write Confirm command is issued. This initiates the WSM
(Write State Machine) to begin copying the buffer data to the flash array. If a command other than
Write Confirm is written to the device, an 鈥淚nvalid Command/Sequence鈥?error will be generated
and SR.5 and SR.4 will be set. For additional buffer writes, issue another Write to Buffer Setup
command and check XSR.7.
If an error occurs while writing, the device will stop writing, and SR.4 will be set to indicate a
program failure. The internal WSM verify only detects errors for 鈥?鈥漵 that do not successfully
program to 鈥?鈥漵. If a program error is detected, the Status Register should be cleared. Any time
SR.4 and/or SR.5 is set (e.g., a media failure occurs during a program or an erase), the device will
not accept any more Write to Buffer commands. Additionally, if the user attempts to program past
an erase block boundary with a Write to Buffer command, the device will abort the write to buffer
operation. This will generate an 鈥淚nvalid Command/Sequence鈥?error and SR.5 and SR.4 will be set.
. If a buffered write is attempted
鈮?/div>
V
PENLK
, SR.4 and SR.3 will be set. Buffered write attempts with invalid V
CC
and
V
PEN
voltages produce spurious results and should not be attempted. Finally, successful
programming requires that the corresponding block lock-bit be reset. If a buffered write is
attempted when the corresponding block lock-bit is set, SR.1 and SR.4 will be set.
11.3
Program Suspend
The Program Suspend command allows program interruption to read data in other flash memory
locations. Once the programming process starts (either by initiating a write to buffer or byte/word
program operation), writing the Program Suspend command requests that the WSM suspend the
program sequence at a predetermined point in the algorithm. The device continues to output SRD
when read after the Program Suspend command is written. Polling SR.7 can determine when the
programming operation has been suspended. When SR.7 = 1, SR.2 should also be set, indicating
that the device is in the program suspend mode. STS in level RY/BY# mode will also transition to
V
OH
. Specification t
WHRH1
defines the program suspend latency.
At this point, a Read Array command can be written to read data from locations other than that
which is suspended. The only other valid commands while programming is suspended are Read
Query, Read Status Register, Clear Status Register, Configure, and Program Resume. After a
Program Resume command is written, the WSM will continue the programming process. SR.2 and
SR.7 will automatically clear and STS in RY/BY# mode will return to V
OL
. After the Program
Resume command is written, the device automatically outputs SRD when read. V
PEN
must remain
at V
PENH
and V
CC
must remain at valid V
CC
levels (the same V
PEN
and V
CC
levels used for
programming) while in program suspend mode. Refer to
Figure 21, 鈥淧rogram Suspend/Resume
Flowchart鈥?on page 62.
11.4
Program Resume
To resume (i.e., continue) a program suspend operation, execute the Program Resume command.
The Resume command can be written to any device address. When a program operation is nested
within an erase suspend operation and the Program Suspend command is issued, the device will
suspend the program operation. When the Resume command is issued, the device will resume and
complete the program operation. Once the nested program operation is completed, an additional
Resume command is required to complete the block erase operation. The device supports a
maximum suspend/resume of two nested routines. See
Figure 21, 鈥淧rogram Suspend/Resume
Flowchart鈥?on page 62).
Datasheet
43