AM29DL640G120EE SPANSION [SPANSION], AM29DL640G120EE Datasheet - Page 31

• Manufacturer Part Number: AM29DL640G120EE
• Description: 64 Megabit (8 M x 8-Bit/4 M x 16-Bit) CMOS 3.0 Volt-only, Simultaneous Read/Write Flash Memory
• Manufacturer: SPANSION [SPANSION]

WRITE OPERATION STATUS
The device provides several bits to determine the status of a
program or erase operation: DQ2, DQ3, DQ5, DQ6, and
DQ7. Table 13 and the following subsections describe the
function of these bits. DQ7 and DQ6 each offer a method for
determining whether a program or erase operation is com-
plete or in progress. The device also provides a hard-
ware-based output signal, RY/BY#, to determine whether
an Embedded Program or Erase operation is in progress or
has been completed.
DQ7: Data# Polling
The Data# Polling bit, DQ7, indicates to the host system
whether an Embedded Program or Erase algorithm is in
progress or completed, or whether a bank is in Erase Sus-
pend. Data# Polling is valid after the rising edge of the final
WE# pulse in the command sequence.
During the Embedded Program algorithm, the device out-
puts on DQ7 the complement 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 program address
falls within a protected sector, Data# Polling on DQ7 is ac-
tive for approximately tPSP µs, then that bank returns to the
read mode.
During the Embedded Erase algorithm, Data# Polling
produces a “0” on DQ7. When the Embedded Erase
algorithm is complete, or if the bank enters the Erase
Suspend mode, Data# Polling produces a “1” on DQ7.
The system must provide an address within any of the
sectors selected for erasure to read valid status infor-
mation on DQ7.
After an erase command sequence is written, if all
sectors selected for erasing are protected, Data# Poll-
ing on DQ7 is active for approximately tASP µs, then
the bank returns to the read mode. If not all selected
sectors are protected, the Embedded Erase algorithm
erases the unprotected sectors, and ignores the se-
lected sectors that are protected. However, if the sys-
tem reads DQ7 at an address within a protected
sector, the status may not be valid.
When the system detects DQ7 has changed from the
complement to true data, it can read valid data at
DQ15–DQ0 (or DQ7–DQ0 for x8-only device) on the
following read cycles. Just prior to the completion of an
Embedded Program or Erase operation, DQ7 may
change asynchronously with DQ15–DQ8 (DQ7–DQ0
for x8-only device) while Output Enable (OE#) is as-
serted low. That is, the device may change from pro-
viding status infor mation to valid data on DQ7.
Depending on when the system samples the DQ7 out-
put, it may read the status or valid data. Even if the de-
June 6, 2005
Am29DL640G
vice has completed the program or erase operation
a n d D Q 7 h a s va l i d d a ta , th e d a t a o u t p u ts o n
D Q1 5–D Q0 may be s ti ll i nva lid . Val id d ata o n
DQ15–DQ0 (or DQ7–DQ0 for x8-only device) will ap-
pear on successive read cycles.
Table 13 shows the outputs for Data# Polling on DQ7.
Figure 6 shows the Data# Polling algorithm. Figure 22
in the AC Characteristics section shows the Data#
Polling timing diagram.
Notes:
1. VA = Valid address for programming. During a sector
2. DQ7 should be rechecked even if DQ5 = “1” because
erase operation, a valid address is any sector address
within the sector being erased. During chip erase, a
valid address is any non-protected sector address.
DQ7 may change simultaneously with DQ5.
No
Figure 6. Data# Polling Algorithm
Read DQ7–DQ0
Read DQ7–DQ0
DQ7 = Data?
DQ7 = Data?
Addr = VA
Addr = VA
DQ5 = 1?
START
FAIL
No
Yes
No
Yes
Yes
PASS
29