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S29WS-N_00_G0 January 25, 2005
Adva nce
Information
VIL. Continuous burst mode can also be aborted by asserting AVD# low and providing a new ad-
dress to the device.
If the address being read crosses a 128-word line boundary (as mentioned above) and the sub-
sequent word line is not being programmed or erased, additional latency cycles are required as
If the address crosses a bank boundary while the subsequent bank is programming or erasing,
the device provides read status information and the clock is ignored. Upon completion of status
read or program or erase operation, the host can restart a burst read operation using a new ad-
dress and AVD# pulse.
7.3.4 8-, 16-, 32-Word Linear Burst Read with Wrap Around
In a linear burst read operation, a fixed number of words (8, 16, or 32 words) are read from con-
secutive addresses that are determined by the group within which the starting address falls. The
groups are sized according to the number of words read in a single burst sequence for a given
For example, if the starting address in the 8-word mode is 3Ch, the address range to be read
would be 38-3Fh, and the burst sequence would be 3C-3D-3E-3F-38-39-3A-3Bh. Thus, the device
outputs all words in that burst address group until all word are read, regardless of where the start-
ing address occurs in the address group, and then terminates the burst read.
In a similar fashion, the 16-word and 32-word Linear Wrap modes begin their burst sequence on
the starting address provided to the device, then wrap back to the first address in the selected
address group.
Note that in this mode the address pointer does not cross the boundary that occurs every 128
words; thus, no additional wait states are inserted due to boundary crossing.
Table 7.7. Burst Address Groups
7.3.5 8-, 16-, 32-Word Linear Burst without Wrap Around
If wrap around is not enabled for linear burst read operations, the 8-word, 16-word, or 32-word
burst executes up to the maximum memory address of the selected number of words. The burst
stops after 8, 16, or 32 addresses and does not wrap around to the first address of the selected
group.
For example, if the starting address in the 8- word mode is 3Ch, the address range to be read
would be 39-40h, and the burst sequence would be 3C-3D-3E-3F-40-41-42-43h if wrap around
is not enabled. The next address to be read requires a new address and AVD# pulse. Note that
in this burst read mode, the address pointer may cross the boundary that occurs every 128 words,
which will incur the additional boundary crossing wait state.
7.3.6 Configuration Register
The configuration register sets various operational parameters associated with burst mode. Upon
power-up or hardware reset, the device defaults to the asynchronous read mode, and the config-
uration register settings are in their default state. The host system should determine the proper
settings for the entire configuration register, and then execute the Set Configuration Register
command sequence, before attempting burst operations. The configuration register is not reset
after deasserting CE#. The Configuration Register can also be read using a command sequence
(see
Table 12.1). The following list describes the register settings.
Mode
Group Size
Group Address Ranges
8-word
8 words
0-7h, 8-Fh, 10-17h,...
16-word
16 words
0-Fh, 10-1Fh, 20-2Fh,...
32-word
32 words
00-1Fh, 20-3Fh, 40-5Fh,...