S29CD016G SPANSION, S29CD016G Datasheet - Page 45

• Manufacturer Part Number: S29CD016G
• Description: 16 Megabit (512 K x 32-Bit) CMOS 2.5 Volt-only Burst Mode / Dual Boot / Simultaneous Read/Write Flash Memory
• Manufacturer: SPANSION

November 5, 2004 S29CD016_00_A4
Accelerated Program Command
Unlock Bypass Command Sequence
trols or timings. The device automatically generates the program pulses and
verifies the programmed cell margin. Tables 8 and 9 show the address and data
requirements for the program command sequence.
During the Embedded Program algorithm, the system can determine the status
of the program operation by using DQ7, DQ6, or RY/BY#. (See
Status” on page 60
Program 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.
Except for Program Suspend, any commands written to the device during the Em-
bedded Program Algorithm are ignored. Note that a hardware reset
immediately terminates the programming operation. The command sequence
should be reinitiated once that bank returns to reading array data, to ensure data
integrity.
Programming is allowed in any sequence and across sector boundaries. A bit
cannot be programmed from a “0” back to a “1”. Attempting to do so may
halt the operation and set DQ5 to “1,” or cause the Data# Polling algorithm to
indicate the operation was successful. However, a succeeding read shows that the
data is still “0”. Only erase operations can convert a “0” to a “1”.
The Accelerated Chip Program mode is designed to improve the Word or Double
Word programming speed. Improving the programming speed is accomplished by
using the ACC pin to supply both the wordline voltage and the bitline current in-
stead of using the V
the external ACC pin is capable of supplying significantly large amounts of current
compared to the drain pump, all 32 bits are available for programming with a sin-
gle programming pulse. This is an enormous improvement over the standard 5-
bit programming. If the user is able to supply an external power supply and con-
nect it to the ACC pin, significant time savings are realized.
In order to enter the Accelerated Program mode, the ACC pin must first be taken
to V
address and data to follow. The Accelerated Chip Program command is only exe-
cuted when the device is in Unlock Bypass mode and during normal read/reset
operating mode.
In this mode, the write protection function is bypassed unless the PPB Lock Bit =
1.
The Accelerated Program command is not permitted if the SecSi sector is
enabled.
The unlock bypass feature allows the system to program words to the device
faster than using the standard program command sequence. The unlock bypass
command sequence is initiated by first writing two unlock cycles. This is followed
by a third write cycle containing the unlock bypass command, 20h. The device
then enters the unlock bypass mode. A two-cycle unlock bypass program com-
mand sequence is all that is required to program in this mode. The first cycle in
this sequence contains the unlock bypass program command, A0h; the second
cycle contains the program address and data. Additional data is programmed in
the same manner. This mode dispenses with the initial two unlock cycles required
HH
(12 V ± 0.5 V) and followed by the one-cycle command with the program
A d v a n c e
PP
for information on these status bits.) When the Embedded
pump and drain pump, which is limited to 2.5 mA. Because
I n f o r m a t i o n
S29CD016G
“Write Operation
45