
November 8, 2007 S29GL-P_00_A7
S29GL-P MirrorBit
 Flash Family
35
D a t a
S h e e t
( P r e l i m i n a r y )
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. 
 It is recommended that WP#/ACC apply V
HH
 after power-up sequence is completed. In addition, it is 
recommended that WP#/ACC apply from V
HH
 to V
IH
/V
IL
 before powering down V
CC
/V
IO
.
7.7.8
Unlock Bypass
This device features an Unlock Bypass mode to facilitate shorter programming commands. 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 Definitions
  on page 67
 shows the requirements for 
the unlock bypass command sequences. 
During the unlock bypass mode, only the Read, Program, Write Buffer Programming, Write-to-Buffer-Abort 
Reset, 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
 (available soon on 
www.spansion.com
) for general 
information on Spansion Flash memory software development guidelines.
/* Example: Unlock Bypass Entry Command    */
  *( (UINT16 *)base_addr + 0x555 ) = 0x00AA;   /* write unlock cycle 1            */
  *( (UINT16 *)base_addr + 0x2AA ) = 0x0055;   /* write unlock cycle 2            */
  *( (UINT16 *)base_addr + 0x555 ) = 0x0020;   /* write unlock bypass command     */
  /* 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.                                               */
Table 7.14  
Unlock Bypass Entry
(LLD Function = lld_UnlockBypassEntryCmd)
Cycle
Description
Operation
Word Address
Data
1
Unlock
Write
Base + 555h
00AAh
2
Unlock
Write
Base + 2AAh
0055h
3
Entry Command
Write
Base + 555h
0020h