S29AL004D90TFI020 Spansion Inc., S29AL004D90TFI020 Datasheet - Page 28
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S29AL004D90TFI020
Manufacturer Part Number
S29AL004D90TFI020
Description
Flash Memory IC
Manufacturer
Spansion Inc.
Specifications of S29AL004D90TFI020
Memory Size
4Mbit
Memory Configuration
512K X 8 / 256K X 16
Ic Interface Type
Parallel
Access Time
90ns
Memory Case Style
TSOP
No. Of Pins
48
Operating Temperature Range
-40°C To +85°C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
S29AL004D90TFI020
Manufacturer:
SPANSION
Quantity:
4 300
Part Number:
S29AL004D90TFI020H
Manufacturer:
SPANSION
Quantity:
20 000
Write Operation Status
26
DQ7: Data# Polling
The device provides several bits to determine the status of a write operation:
DQ2, DQ3, DQ5, DQ6, DQ7, and RY/BY#.
subsections describe the functions of these bits. DQ7, RY/BY#, and DQ6 each
offer a method for determining whether a program or erase operation is complete
or in progress. These three bits are discussed first.
The Data# Polling bit, DQ7, indicates to the host system whether an Embedded
Algorithm is in progress or completed, or whether the device is in Erase Suspend.
Data# Polling is valid after the rising edge of the final WE# pulse in the program
or erase command sequence.
During the Embedded Program algorithm, the device outputs on DQ7 the com-
plement of the datum programmed to DQ7. This DQ7 status also applies to
programming during Erase Suspend. When the Embedded Program algorithm is
complete, the device outputs the datum programmed to DQ7. The system must
provide the program address to read valid status information on DQ7. If a pro-
gram address falls within a protected sector, Data# Polling on DQ7 is active for
approximately 1 µs, then the device returns to reading array data.
During the Embedded Erase algorithm, Data# Polling produces a 0 on DQ7. When
the Embedded Erase algorithm is complete, or if the device enters the Erase Sus-
pend mode, Data# Polling produces a 1 on DQ7. This is analogous to the
complement/true datum output described for the Embedded Program algorithm:
the erase function changes all the bits in a sector to 1; prior to this, the device
outputs the complement, or 0. The system must provide an address within any
of the sectors selected for erasure to read valid status information on DQ7.
After an erase command sequence is written, if all sectors selected for erasing
are protected, Data# Polling on DQ7 is active for approximately 100 µs, then the
device returns to reading array data. If not all selected sectors are protected, the
Embedded Erase algorithm erases the unprotected sectors, and ignores the se-
lected sectors that are protected.
When the system detects DQ7 has changed from the complement to true data,
it can read valid data at DQ7–DQ0 on the following read cycles. This is because
DQ7 may change asynchronously with DQ0–DQ6 while Output Enable (OE#) is
asserted low.
Embedded Algorithms), in
Table 6 on page 31
page 27
shows the Data# Polling algorithm.
Figure 19, on page
shows the outputs for Data# Polling on DQ7.
AC Characteristics‚ on page 37
A d v a n c e
S29AL004D
44, Data# Polling Timings (During
Table 6 on page 31
I n f o r m a t i o n
illustrates this.
and the following
Figure 5, on
S29AL004D_00_A1 February 18, 2005