NX25F080A 데이터 시트보기 (PDF) - NexFlash -> Winbond Electronics
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NX25F080A Datasheet PDF : 25 Pages
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NX25F080A
Write to Sector
Before writing to a sector in the Flash memory array, all
hardware and software write protection must be in an
enabled state. This means that the WP pin must be in a high
state, a Write Enable command must have previously been
issued, and the sector location that is to be written to must be
outside the write protect range set in the Configuration
Register. Additionally, the Ready/Busy status should be
checked to confirm that the memory array is available to be
written to.
The bit order within each byte is most significant bit first
1 (i.e., D7,...D0). The byte-address is automatically incre-
mented to the next higher byte address as the clock
continues. When the last byte address to be written is
reached, the command can be completed with an
2 additional eight control clocks (with data=0) followed by
asserting CS high. If the clock continues to increment
past the highest byte-address (217H), the address
counter will roll over to byte 0H.
Writing to a sector is accomplished by first bringing CS low
and shifting in the Write to Sector command (F3H)
followed by a 16-bit “sector-address” field. Although the
sector-address field is 16-bits, only bits S[10:0] for the
NX25F080A (0-7FFH) are used. The uppermost sector
address bits are not used but must be clocked in
(use 0 for data). Following the sector address, a 16-bit
“byte-address” field is clocked into the device to designate
the starting location within the 536-byte sector. Only bits
B[9:0] of the byte-address field are used and only values
of 0-217H (536 bytes) are valid.
3 After the CS pin is brought high, the data in the SRAM is
automatically transferred to the Program Buffer, which
handles the self-timed programming of the specified sector
4 in memory array. See tWP timing specifications. During
this time the array will be “busy” and will ignore further
array-related commands until complete. All Ready/Busy
status indicators will indicate a busy status. Since the
5 Program Buffer handles all array programming, the
SRAM is still available to be read from or written to during
the busy state. This allows the SRAM to be written to in
preparation of the next sector write. Once the SRAM is
After the byte-address has been loaded, data is shifted
into the 536-byte SRAM, which serves as a temporary
loaded, its contents can be transferred to a selected
6 sector using the Transfer SRAM to Sector command.
Note that if the write operation is to be verified the contents
storage buffer. Existing data in the SRAM will be written of the SRAM should be maintained. Detailed clock timing
over. The byte order of the data shifted into the SRAM is for the Write to Sector command in shown in Figure 11.
least significant byte first (i.e., byte-00H, byte-01H,...).
7
Write to
Sector
Sector
Byte
Program
Command
SI
F3H
Address*
S[15:0]
Address**
B[15:0]
Write Sector Data
First Byte - Last Byte
8 Clocks
Time
00H
(tWP)
8
SO
*The sector address only uses bits [10:0]
9
**The byte address only uses bits [9:0]
Transfer SRAM to Sector
The Transfer SRAM to Sector command (F3H) will write
the existing contents of the SRAM to the specified
sector in memory. The command sequence is identical
to that of the Write to Sector command except that
immediately after the sector address field S[15:0] and
16 control clocks, the CS pin is asserted high. This
automatically transfers the 536-bytes of SRAM data to
the Program Buffer, which handles the programming of
the specified sector in the memory array. During this
time, the array will be busy. Since the entire 536-bytes
are transferred, the byte-address field B[15:0]
is not used
NexFlash Technologies, Inc.
PRELIMINARY NXSF005C-0699
06/11/99 ©
Transfer SRAM
to Sector
Sector
Command Address*
SI
F3H
S[15:0]
16 Clocks
0000H
Program Time
(tWP)
10
11
SO
*The sector address only uses bits [10:0]
12
13
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