128Mb, 256Mb, 512Mb, 1Gb StrataFlash Memory
Programming Modes
Programming Modes
Each programming region in a block can be configured for either control mode or ob-
ject mode.
The programming mode is automatically set based on the data pattern when a region is
first programmed. Selecting either control mode or object mode is done according to
the specific needs of the system. In control mode, code or data is frequently changed
(such as the flash file system or header information). In object mode, large code or data
(such as objects or payloads) is infrequently changed. By implementing the appropriate
programming mode, software can efficiently organize how information is stored in the
memory array.
Control mode programming regions and object mode programming regions can be in-
termingled within the same erase block. However, the programming mode of any region
within a block can be changed only after erasing the entire block.
Control Mode
Control mode programming is invoked when only the A-half (A3 = 0) of the program-
ming region is programmed to 0s. The B-half (A3 = 1) remains erased. Control mode al-
lows up to 512 bytes of data to be programmed in the region. The information can be
programmed in bits, bytes, or words.
Control mode supports the following programming methods:
• Single-word programming (0041h)
• Buffered programming (00E9h/00D0h)
• Buffered enhanced factory programming (0080h/00D0h)
When buffered programming is used in control mode, all addresses must be in the A-
half of the buffer (A3 = 0). During buffer fill, the B-half (A3 = 1) addresses do not need to
be filled with 0xFFFF.
Control mode programming is useful for storing dynamic information, such as flash file
system headers, file Info, and so on. Typically, control mode programming does not re-
quire the entire 512 bytes of data to be programmed at once. It may also contain data
that is changed after initial programming using a technique known as “bit twiddling”.
Header information can be augmented later with additional new information within a
control-mode-programmed region. This allows implementation of legacy file systems,
as well as transaction-based power-loss recovery.
In a control mode region, PROGRAM operations can be performed multiple times.
However, care must be taken to avoid programming any zeros in the B-half (A3 = 1) of
the region. Violation of this usage will cause SR[4] and SR[9] to be set, and the PRO-
GRAM operation will be aborted.
PDF: 09005aef8448483a
128_256_512_65nm_g18.pdf - Rev. F 8/11 EN
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