Cypress S29GL01GP, Руководство пользователя

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Document Number: 002-00886 Rev. *B Page 23 of 83
S29GL01GP
S29GL512P
S29GL256P
S29GL128P
Write buffer programming is allowed in any sequence of memory (or address) locations. These flash devices are capable of handling
multiple write buffer programming operations on the same write buffer address range without intervening erases.
Use of the write buffer is strongly recommended for programming when multiple words are to be programmed.
Software Functions and Sample Code
Notes
1. Base = Base Address.
2. Last = Last cycle of write buffer program operation; depending on number of words written, the total number of cycles may be from 6 to 37.
3.
For maximum efficiency, it is recommended that the write buffer be loaded with the highest number of words (N words) possible
.
The following is a C source code example of using the write buffer program function. Refer to the
Cypress Low Level Driver User’s
Guide
(available on www.cypress.com ) for general information on Cypress Flash memory software development guidelines.
/* Example: Write Buffer Programming Command */
/* NOTES: Write buffer programming limited to 16 words. */
/* All addresses to be written to the flash in */
/* one operation must be within the same flash */
/* page. A flash page begins at addresses */
/* evenly divisible by 0x20. */
UINT16 *src = source_of_data; /* address of source data */
UINT16 *dst = destination_of_data; /* flash destination address */
UINT16 wc = words_to_program -1; /* word count (minus 1) */
*( (UINT16 *)bas 0x555 ) = 0x00AA; /* write unlock cycle 1 */
*( (UINT16 *)bas 0x2AA ) = 0x0055; /* write unlock cycle 2 */
*( (UINT16 *)sector_address ) = 0x0025; /* write write buffer load command */
*( (UINT16 *)sector_address ) = wc; /* write word count (minus 1) */
for (i=0;i<=wc;i++)
{
*dst++ = *src++; /* ALL dst MUST BE in same Write Buffer */
}
*( (UINT16 *)sector_address ) = 0x0029; /* write confirm command */
/* poll for completion */
/* Example: Write Buffer Abort Reset */
*( (UINT16 *)addr + 0x555 ) = 0x00AA; /* write unlock cycle 1 */
*( (UINT16 *)addr + 0x2AA ) = 0x0055; /* write unlock cycle 2 */
*( (UINT16 *)addr + 0x555 ) = 0x00F0; /* write buffer abort reset */
Write Buffer Program
(LLD Functions Used = lld_WriteToBufferCmd, lld_ProgramBufferToFlashCmd)
Cycle Description Operation Byte Address Word Address Data
1 Unlock Write Base + AAAh Base + 555h 00AAh
2 Unlock Write Base + 555h Base + 2AAh 0055h
3 Write Buffer Load Command Write Sector Address 0025h
4 Write Word Count Write Sector Address Word Count (N–1)h
Number of words (N) loaded into the write buffer can be from 1 to 32 words (1 to 64 bytes).
5 to 36 Load Buffer Word N Write Program Address, Word N Word N
Last Write Buffer to Flash Write Sector Address 0029h