
DD28F032SA
E
6
The DD28F032SA provides user-selectable block
locking to protect code or data such as device
drivers,
PCMCIA
card
executable O/S or application code. Each block
has an associated nonvolatile lock-bit which
determines the lock status of the block. In
addition, the DD28F032SA has a master Write
Protect
pin
(WP#)
modifications to memory blocks whose lock-bits
are set.
information,
ROM-
which
prevents
any
The DD28F032SA contains three types of Status
Registers to accomplish various functions:
A Compatible Status Register (CSR) which is
100% compatible with the 28F008SA FlashFile
memory’s Status Register. This register, when
used alone, provides a straightforward upgrade
capability
to
the
DD28F032SA
28F008SA-based design.
A Global Status Register (GSR) which informs
the system of Command Queue status, Page
Buffer status, and overall Write State Machine
(WSM) status.
64 Block Status Registers (BSRs) which
provide block-specific status information such
as the block lock-bit status.
from
a
The GSR and BSR memory maps for byte-wide
and word-wide modes are shown in Figures 4
and 5.
The DD28F032SA incorporates an open drain
RY/BY# output pin. This feature allows the user to
OR-tie many RY/BY# pins together in a multiple
memory configuration such as a Resident Flash
Array. Other configurations of the RY/BY# pin are
enabled via special CUI commands and are
described in detail in the
16-Mbit Flash Product
Family User’s Manual
.
The DD28F032SA also incorporates three chip-
enable input pins, CE
#, CE
# and CE
#. The
active low combination of CE
# and CE
# controls
the first 28F016SA. The active low combination of
CE
0
# and CE
2
# controls the second 28F016SA.
The BYTE# pin allows either x8 or x16
read/programs to the DD28F032SA. BYTE# at
logic low selects 8-bit mode with address A
0
selecting between low byte and high byte. On the
other hand, BYTE# at logic high enables 16-bit
operation with address A
becoming the lowest
order address and address A
is not used (don’t
care). A device block diagram is shown in Figure
1
.
The DD28F032SA is specified for a maximum
access time of 70 ns (t
ACC
) at 5.0V operation
(4.75V to 5.25V) over the commercial temperature
range (0°C to +70°C). A corresponding maximum
access time of 150 ns at 3.3V (3.0V to 3.6V and
0°C to +70°C) is achieved for reduced power
consumption applications.
The DD28F032SA incorporates an Automatic
Power Saving (APS) feature which substantially
reduces the active current when the device is in
static
mode
of
operation
switching).
(addresses
not
A deep power-down mode of operation is invoked
when the RP# (called PWD# on the 28F008SA)
pin is driven low. This mode provides additional
write protection by acting as a device reset pin
during power transitions. In the deep power-down
state, the WSM is reset (any current operation will
abort) and the CSR, GSR and BSR registers are
cleared.
A CMOS standby mode of operation is enabled
when either CE
#, or both CE
# and CE
#,
transition high and RP# stays high with all input
control pins at CMOS levels.
2.0 DEVICE PINOUT
The DD28F032SA Standard 56-Lead Dual Die
TSOP Type I pinout configuration is shown in
Figure 2.