Data
Sheet
(Advan ce
Infor m a tio n)
7.7.7
Accelerated Program
Accelerated single word programming and write buffer programming operations are enabled through the
WP#/ACC pin. This method is faster than the standard program command sequences.
Note
The accelerated program functions must not be used more than 10 times per sector.
If the system asserts V
HH
on this input, the device automatically enters the aforementioned Unlock Bypass
mode and uses the higher voltage on the input to reduce the time required for program operations. The
system can then use the Write Buffer Load command sequence provided by the Unlock Bypass mode. Note
that if a “Write-to-Buffer-Abort Reset” is required while in Unlock Bypass mode, the full 3-cycle RESET
command sequence must be used to reset the device. Removing V
HH
from the ACC input, upon completion
of the embedded program operation, returns the device to normal operation.
Sectors must be unlocked prior to raising WP#/ACC to V
HH
.
The WP#/ACC pin must not be at V
HH
for operations other than accelerated programming, or device
damage may result.
The WP#/ACC pin must not be left floating or unconnected; inconsistent behavior of the device may result.
7.7.8
Unlock Bypass
The device features an Unlock Bypass mode to facilitate faster word programming. Once the device enters
the Unlock Bypass mode, only two write cycles are required to program data, instead of the normal four
cycles.
This mode dispenses with the initial two unlock cycles required in the standard program command sequence,
resulting in faster total programming time. The “Command Definition Summary” section shows the
requirements for the unlock bypass command sequences.
During the unlock bypass mode, only the Read, Unlock Bypass Program and Unlock Bypass Reset
commands are valid. To exit the unlock bypass mode, the system must issue the two-cycle unlock bypass
reset command sequence. The first cycle must contain the sector address and the data 90h. The second
cycle need only contain the data 00h. The sector then returns to the read mode.
Software Functions and Sample Code
The following are C source code examples of using the unlock bypass entry, program, and exit functions.
Refer to the
Spansion Low Level Driver User’s Guide
www.spansion.com)
for general
information on Spansion Flash memory software development guidelines.
Table 7.14
Unlock Bypass Entry
(LLD Function = lld_UnlockBypassEntryCmd)
Cycle
1
2
3
Description
Unlock
Unlock
Entry Command
Operation
Write
Write
Write
Word Address
Base + 555h
Base + 2AAh
Base + 555h
Data
00AAh
0055h
0020h
/* Example: Unlock Bypass Entry Command
*/
*( (UINT16 *)base_addr + 0x555 ) = 0x00AA;
/* write unlock
*( (UINT16 *)base_addr + 0x2AA ) = 0x0055;
/* write unlock
*( (UINT16 *)base_addr + 0x555 ) = 0x0020;
/* write unlock
/* At this point, programming only takes two write cycles.
/* Once you enter Unlock Bypass Mode, do a series of like
/* operations (programming or sector erase) and then exit
/* Unlock Bypass Mode before beginning a different type of
/* operations.
cycle 1
cycle 2
bypass command
*/
*/
*/
*/
*/
*/
*/
*/
30
S29GL-P MirrorBit
TM
Flash Family
S29GL-P_00_A3 November 21, 2006
SPANSION [ SPANSION ]
