D a t a S h e e t ( P r e l i m i n a r y )
Software Functions and Sample Code
Table 7.6 Single Word/Byte Program
(LLD Function = lld_ProgramCmd)
Cycle
Operation
Write
Byte Address
Base + AAAh
Base + 555h
Base + AAAh
Byte Address
Word Address
Base + 555h
Base + 2AAh
Base + 555h
Word Address
Data
00AAh
0055h
00A0h
Data
Unlock Cycle 1
Unlock Cycle 2
Program Setup
Program
Write
Write
Write
Note
Base = Base Address.
The following is a C source code example of using the single word program function. Refer to the Spansion
Low Level Driver User’s Guide (available on www.spansion.com) for general information on Spansion Flash
memory software development guidelines.
/* Example: Program Command
*/
*( (UINT16 *)base_addr + 0x555 ) = 0x00AA;
*( (UINT16 *)base_addr + 0x2AA ) = 0x0055;
*( (UINT16 *)base_addr + 0x555 ) = 0x00A0;
/* write unlock cycle 1
*/
*/
*/
*/
/* write unlock cycle 2
/* write program setup command
/* write data to be programmed
*( (UINT16 *)pa )
= data;
/* Poll for program completion */
7.7.2
Write Buffer Programming
Write Buffer Programming allows the system to write a maximum of 32 words in one programming operation.
This results in a faster effective word programming time than the standard “word” programming algorithms.
The Write Buffer Programming command sequence is initiated by first writing two unlock cycles. This is
followed by a third write cycle containing the Write Buffer Load command written at the Sector Address in
which programming occurs. At this point, the system writes the number of “word locations minus 1” that are
loaded into the page buffer at the Sector Address in which programming occurs. This tells the device how
many write buffer addresses are loaded with data and therefore when to expect the “Program Buffer to Flash”
confirm command. The number of locations to program cannot exceed the size of the write buffer or the
operation aborts. (Number loaded = the number of locations to program minus 1. For example, if the system
programs 6 address locations, then 05h should be written to the device.)
The system then writes the starting address/data combination. This starting address is the first address/data
pair to be programmed, and selects the “write-buffer-page” address. All subsequent address/data pairs must
fall within the elected-write-buffer-page.
The “write-buffer-page” is selected by using the addresses AMAX–A5.
The “write-buffer-page” addresses must be the same for all address/data pairs loaded into the write buffer.
(This means Write Buffer Programming cannot be performed across multiple “write-buffer-pages.” This also
means that Write Buffer Programming cannot be performed across multiple sectors. If the system attempts to
load programming data outside of the selected “write-buffer-page”, the operation ABORTs.)
After writing the Starting Address/Data pair, the system then writes the remaining address/data pairs into the
write buffer.
Note that if a Write Buffer address location is loaded multiple times, the “address/data pair” counter is
decremented for every data load operation. Also, the last data loaded at a location before the “Program Buffer
to Flash” confirm command is the data programmed into the device. It is the software's responsibility to
comprehend ramifications of loading a write-buffer location more than once. The counter decrements for each
data load operation, NOT for each unique write-buffer-address location. Once the specified number of write
buffer locations have been loaded, the system must then write the “Program Buffer to Flash” command at the
Sector Address. Any other address/data write combinations abort the Write Buffer Programming operation.
The Write Operation Status bits should be used while monitoring the last address location loaded into the
write buffer. This eliminates the need to store an address in memory because the system can load the last
address location, issue the program confirm command at the last loaded address location, and then check
the write operation status at that same address. DQ7, DQ6, DQ5, DQ2, and DQ1 should be monitored to
determine the device status during Write Buffer Programming.
26
S29GL-P MirrorBit® Flash Family
S29GL-P_00_A7 November 8, 2007
SPANSION [ SPANSION ]
