AM29BDD160G AMD [Advanced Micro Devices], AM29BDD160G Datasheet - Page 39

• Manufacturer Part Number: AM29BDD160G
• Description: 16 Megabit (1 M x 16-bit/512 K x 32-Bit), CMOS 2.5 Volt-only Burst Mode, Dual Boot, Simultaneous Read/Write Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

Automatic sector erase operations begin on the ris-
ing edge of the WE# or CE# pulse of the last sector
erase command issued, and once the 80 µs time-out
window has expired. The status of the sector erase
operation is determined three ways:
Further status of device activity during the sector
erase operation is determined using toggle bit DQ2
(refer to
When the Embedded Erase algorithm is complete,
the device returns to reading array data, and ad-
dresses are no longer latched. Note that an address
change is required to begin read valid array data.
Figure 5 illustrates the Embedded™ Erase Algorithm,
using a typical command sequence and bus opera-
tion. Refer to the
the
Figure 22 for timing diagrams.
Note:
1. See Tables 18 and 20 for erase command sequence.
2. See
Sector Erase and Program Suspend
Command
The Sector Erase and Program Suspend command
allows the user to interrupt a Sector Erase or Pro-
gram operation and perform data read or programs
in a sector that is not being erased or to the sector
where a programming operation was initiated. This
command is applicable only during the Sector Erase
Data# polling of the DQ7 pin
Checking the status of the toggle bit DQ6
Checking the status of the RY/BY# pin
AC Characteristics
DQ3: Sector Erase Timer
DQ2: Toggle Bit
Figure 5. Erase Operation
Erase/Program Operations
section for parameters, and to
II).
for more information.
Embedded
Erase
algorithm in
progress
tables in
Am29BDD160G
and Programming operation, which includes the
time-out period for Sector Erase.
Sector Erase and Program Suspend
Operation Mechanics
The counter is incremented by one every time an
erase pulse is initiated, regardless of whether or not
that erase pulse is successful. An erase pulse is ter-
minated immediately when the suspend command is
executed. A new erase pulse is initiated when the re-
sume command is executed (and the counter is
incremented).
Given that 300 successful erase pulses are required,
a successful sector erase operation shall have a
maximum of 5680 erase suspends.
The Sector Erase and Program Suspend command is
ignored if written during the execution of the Chip
Erase operation or Embedded Program Algorithm
(but will reset the chip if written improperly during
the command sequences). Writing the Sector Erase
and Program command during the Sector Erase
time-out results in immediate termination of the
time-out period and suspension of the erase opera-
tion. Once in Erase Suspend, the device is available
for reading (note that in the Erase Suspend mode,
the Reset command is not required for read opera-
tions and is ignored) or program operations in
sectors not being erased. Any other command writ-
ten during the Erase Suspend mode is ignored,
except for the Sector Erase and Program Resume
command. Writing the Erase and Program Resume
command resumes the sector erase operation. The
bank address of the erase suspended bank is re-
quired when writing this command
If the Sector Erase and Program Suspend command
is written during a programming operation, the de-
vice suspends programming operations and allows
only read operations in sectors not selected for pro-
gramming. Further nesting of either erase or
programming operations is not permitted. Table 18
summarizes permissible operations during Erase and
Program Suspend. (A busy sector is one that is se-
lected for programming or erasure.):
Busy Sector
Non-busy
Table 18. Allowed Operations During
Sector
sectors
A successful erase pulse has a duration or 1.2 ms
± 20%, depending on the number of previous
erase cycles (among other factors).
A successful sector erase operation requires 300
successful erase pulses.
An internal counter monitors the number of erase
pulses initiated and has a maximum value of
5980.
Erase/Program Suspend
Program Suspend
Program Resume
Read Only
Read or Program
Erase Suspend
Erase Resume
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