S29PL-J SPANSION [SPANSION], S29PL-J Datasheet - Page 54

• Manufacturer Part Number: S29PL-J
• Description: CMOS 3.0 Volt-only, Simultaneous-Read/Write Flash Memory with Enhanced VersatileIO Control
• Manufacturer: SPANSION [SPANSION]

13.7
14. Common Flash Memory Interface (CFI)
52
13.7.1
13.7.2
13.7.3
13.7.4
Hardware Data Protection
Low V
Write Pulse “Glitch” Protection
Logical Inhibit
Power-Up Write Inhibit
The command sequence requirement of unlock cycles for programming or erasing provides data protection
against inadvertent writes. In addition, the following hardware data protection measures prevent accidental
erasure or programming, which might otherwise be caused by spurious system level signals during V
power-up and power-down transitions, or from system noise.
When V
power-up and power-down. The command register and all internal program/erase circuits are disabled, and
the device resets to the read mode. Subsequent writes are ignored until V
system must provide the proper signals to the control pins to prevent unintentional writes when V
than V
Noise pulses of less than 3 ns (typical) on OE#, CE#, (CE1#, CE2# in PL129J) or WE# do not initiate a write
cycle.
Write cycles are inhibited by holding any one of OE# = V
V
logical one.
If WE# = CE# (CE1#, CE2# in PL129J) = V
commands on the rising edge of WE#. The internal state machine is automatically reset to the read mode on
power-up.
The Common Flash Interface (CFI) specification outlines device and host system software interrogation
handshake, which allows specific vendor-specified software algorithms to be used for entire families of
devices. Software support can then be device-independent, JEDEC ID-independent, and forward- and
backward-compatible for the specified flash device families. Flash vendors can standardize their existing
interfaces for long-term compatibility.
This device enters the CFI Query mode when the system writes the CFI Query command, 98h, to address
55h, any time the device is ready to read array data. The system can read CFI information at the addresses
given in
write the reset command. The CFI Query mode is not accessible when the device is executing an Embedded
Program or embedded Erase algorithm.
The system can also write the CFI query command when the device is in the autoselect mode. The device
enters the CFI query mode, and the system can read CFI data at the addresses given in
Table
For further information, please refer to the CFI Specification and CFI Publication 100. Contact your local sales
office for copies of these documents.
IH
. To initiate a write cycle, CE# (CE1# / CE2# in PL129J) and WE# must be a logical zero while OE# is a
14.4. The system must write the reset command to return the device to reading array data.
LKO
CC
CC
Table 14.1 on page 53
.
Write Inhibit
is less than V
D a t a
LKO
, the device does not accept any write cycles. This protects data during V
to
S h e e t
Table 14.4 on page
S29PL-J
IL
and OE# = V
( A d v a n c e
54. To terminate reading CFI data, the system must
IL
, CE# (CE1# = CE2# in PL129J)= V
IH
during power up, the device does not accept
I n f o r m a t i o n )
S29PL-J_00_A9 September 22, 2006
CC
is greater than V
Table 14.1
LKO
IH
CC
or WE# =
. The
is greater
to
CC
CC