Micron M25P40 Serial Flash Embedded Memory
PAGE PROGRAM
PAGE PROGRAM
The PAGE PROGRAM command allows bytes in the memory to be programmed, which
means the bits are changed from 1 to 0. Before a PAGE PROGRAM command can be ac-
cepted a WRITE ENABLE command must be executed. After the WRITE ENABLE com-
mand has been decoded, the device sets the write enable latch (WEL) bit.
The PAGE PROGRAM command is entered by driving chip select (S#) LOW, followed by
the command code, three address bytes, and at least one data byte on serial data input
(DQ0).
If the eight least significant address bits (A7-A0) are not all zero, all transmitted data that
goes beyond the end of the current page are programmed from the start address of the
same page; that is, from the address whose eight least significant bits (A7-A0) are all
zero. S# must be driven LOW for the entire duration of the sequence.
If more than 256 bytes are sent to the device, previously latched data are discarded and
the last 256 data bytes are guaranteed to be programmed correctly within the same
page. If less than 256 data bytes are sent to device, they are correctly programmed at the
requested addresses without any effects on the other bytes of the same page.
For optimized timings, it is recommended to use the PAGE PROGRAM command to
program all consecutive targeted bytes in a single sequence rather than to use several
PAGE PROGRAM sequences, each containing only a few bytes.
S# must be driven HIGH after the eighth bit of the last data byte has been latched in.
Otherwise the PAGE PROGRAM command is not executed.
As soon as S# is driven HIGH, the self-timed PAGE PROGRAM cycle is initiated; the cy-
cles's duration is t
PP
. While the PAGE PROGRAM cycle is in progress, the status register
may be read to check the value of the write in progress (WIP) bit. The WIP bit is 1 during
the self-timed PAGE PROGRAM cycle, and 0 when the cycle is completed. At some un-
specified time before the cycle is completed, the write enable latch (WEL) bit is reset.
A PAGE PROGRAM command is not executed if it applies to a page protected by the
block protect bits BP2, BP1, and BP0.
Figure 15: PAGE PROGRAM Command Sequence
0
C
7
8
C
x
LSB
DQ[0]
MSB
Command
A[MAX]
A[MIN]
D
IN
MSB
D
IN
D
IN
D
IN
D
IN
D
IN
D
IN
D
IN
LSB
D
IN
Note:
1. Cx = 7 + (A[MAX] + 1).
PDF: 09005aef8456654f
m25p40.pdf - Rev. Y 8/12 EN
28
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