NP8P128A13BSM60E Datasheet, PDF (26/92 Pages) Numonyx B.V – 128-Mbit Parallel Phase Change Memory

Numonyx® Omneo™ P8P Datasheet
Successful programming requires that the addressed block’s locking status to be
cleared. If the block is locked down, then the WP# pin must be raised high and then the
block could be unlocked to execute a program operation. An attempt to program a
locked block results in setting of SR.4 and SR.1 to a ‘1’ (i.e. “Error in Programming”).
8.4
Bit Alterable Buffer Write
The Bit Alterable Buffer Write command sequence is the same as for Buffer Program.
For command sequence see Section 8.3, “Buffered Program Command” on page 25.
The primary difference between the two Buffer commands is when the Write State
Machine starts executing, the data written to the buffer will be directly overwritten into
the PCM memory, unlike Flash Memory, which can only go from “1” to “0” before an
erase of the entire block. See Table 12, “Bit Alterability vs. Flash Bit-Masking” on
page 26. This overwrite function eliminates Flash Bit Masking, which means software
cannot use a “1” in a data mask for no change of the memory cell, as might occur with
floating gate flash.
The advantage of Bit Alterability is no block erase is needed prior to writing a block,
which minimizes system overhead for software management of data, and ultimately
improves latency, determinism, and reduces power consumption because of reduction
of system overhead. Storing of counter variables can easily be handled by using PCM
memory because a “0” can change to a “1” or a “1” can change to a “0”.
Table 11: Buffered Programming and Bit Alterable Buffer Write Timing Requirements
Alignment
32-word/64-byte Aligned
Programming Time
t_PROG/PB
Example
Start Address = 1FFF10h; End Address = 1FFF2Fh
Table 12: Bit Alterability vs. Flash Bit-Masking
Programming
Function
Command
Issued
40h or E8h
40h or E8h
40h or E8h
40h or E8h
42h or EAh
42h or EAh
42h or EAh
42h or EAh
Memory Cell
Current State
0
0
1
1
0
0
1
1
Data From
User
0
1
0
1
0
1
0
1
Memory Cell
After Programming
0
0
0
1
0
1
0
1
8.5
Bit Alterable Buffer Program
This mode is sometimes referred to as PreSET Buffered Program.
‘Program on all 1s’ is similar to program mode (“1”s treated as masks; “0”s written to
cells) with the assumption that all the locations in the addressed page have previously
been SET (“1”s). [Performance of Buffer Program on All 1s expected to be better than
buffered program mode because the pre-read step before programming is eliminated.]
The command sequence for Buffered Program on all 1s is the same as Buffered
Program Command (E8h).
Datasheet
26
July 2010
316144-07