E S I
E S I
ADVANCED INFORMATION
Excel Semiconductor inc.
If fewer than 256 data bytes are sent to device, they
are correctly programmed at the requested
addresses without having any effects on the other
bytes of the same page.
Page Program (PP)
The Page Program (PP) instruction allows bytes to
be programmed in the memory (changing from 1 to
0). Before it can be accepted, a Write Enable
(WREN) instruction must previously have been exe-
cuted. After the Write Enable (WREN) instruction
has been decoded, the device sets the Write Enable
Latch (WEL).
Chip Select (CS#) must be driven High after the
eighth bit of the last data byte has been latched in,
otherwise the Page Program (PP) instruction is not
executed. As soon as Chip Select (CS#) is driven
High, the self-timed Page Program cycle (whose
duration is t ) is initiated. While the Page Program
The Page Program (PP) instruction is entered by
driving Chip Select (CS#) Low, followed by the
instruction code, three address bytes and at least
one data byte on Serial Data Input (SI). Chip Select
(CS#) must be driven Low for the entire duration of
the sequence.
PP
cycle is in progress, the Status Register may be
read to check the value of the Write In Progress
(WIP) bit. The Write In Progress (WIP) bit is 1 dur-
ing the self-timed Page Program cycle, and is 0
when it is completed. At some unspecified time
before the cycle is completed, the Write Enable
Latch (WEL) bit is reset.
The instruction sequence is shown in Figure 13.
A Page Program (PP) instruction applied to a page
that is protected by the Block Protect (BP2, BP1,
BP0) bits (see Table 1) is not executed.
If more that 256 data bytes are sent to the device,
the addressing will wrap to the beginning of the
same page, previously latched data are discarded
and the last 256 data bytes are guaranteed to be
programmed correctly within the same page.
CS#
0
0
1
2
3
4
5
6
7
8
9
10
28 29 30 31 32 33 34 35 36 37 38 39
SCK
SI
Data Byte1
Instruction
24-Bit Address
0
0
0
0
0
1
0
1
4
2
0
1
7
5
3
22 21
0
6
23
2
MSB
MSB
CS#
SCK
40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
Data Byte 2
Data Byte 3
Data Byte256
1
4
2
0
1
7
6
5
3
4
2
0
1
7
5
3
4
2
0
6
SI
7
5
3
6
MSB
MSB
MSB
Figure 13. Page Program (PP) Instruction Sequence
18
Rev. 0E May 11 , 2006
ES25P16
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