s71ws256nc0bawa30 Meet Spansion Inc., s71ws256nc0bawa30 Datasheet - Page 32

• Manufacturer Part Number: s71ws256nc0bawa30
• Description: Stacked Multi-chip Product Mcp 256/512/128 Megabit 32m/16m/8m X 16 Bit Cmos 1.8 Volt-only Simultaneous Read/write, Burst-mode Flash Memory With 128/64megabit 8m/4m X 16-bit Psram.
• Manufacturer: Meet Spansion Inc.

30
10.3.4
10.3.5
10.3.6
Continuous Burst Read Mode
In the continuous burst read mode, the device outputs sequential burst data from the starting
address given and then wrap around to address 000000h when it reaches the highest addressable
memory location. The burst read mode continues until the system drives CE# high, or RESET=
V
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
reflected by the configuration register table
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.
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
mode (see
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.
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.
IL
. Continuous burst mode can also be aborted by asserting AVD# low and providing a new ad-
16-word
32-word
8-word
Mode
Table
10.8).
Group Size
16 words
32 words
8 words
Table 10.8 Burst Address Groups
A d v a n c e
S71WS-Nx0 Based MCPs
Group Address Ranges
0-7h, 8-Fh, 10-17h,...
0-Fh, 10-1Fh, 20-2Fh,...
00-1Fh, 20-3Fh, 40-5Fh,...
(Table
I n f o r m a t i o n
10.9).
S71WS-N_01_A4 September 15, 2005