Document Number: 001-98285 Rev. *R
S29GL01GS/S29GL512S
S29GL256S/S29GL128S
The device control logic is subdivided into two parallel operating sections, the Host Interface Controller (HIC) and the Embedded
Algorithm Controller (EAC). HIC monitors signal levels on the device inputs and drives outputs as needed to complete read and write
data transfers with the host system. HIC delivers data from the currently entered address map on read transfers; places write
transfer address and data information into the EAC command memory; notifies the EAC of power transition, hardware reset, and
write transfers. The EAC looks in the command memory, after a write transfer, for legal command sequences and performs the
related Embedded Algorithms.
Changing the non-volatile data in the memory array requires a complex sequence of operations that are called Embedded
Algorithms (EA). The algorithms are managed entirely by the device internal EAC. The main algorithms perform programming and
erase of the main array data. The host system writes command codes to the flash device address space. The EAC receives the
commands, performs all the necessary steps to complete the command, and provides status information during the progress of an
EA.
The erased state of each memory bit is a logic 1. Programming changes a logic 1 (High) to a logic 0 (Low). Only an Erase operation
is able to change a 0 to a 1. An erase operation must be performed on an entire 128-kbyte aligned and length group of data call a
Sector. When shipped from Cypress all Sectors are erased.
Programming is done via a 512-byte Write Buffer. It is possible to write from 1 to 256 words, anywhere within the Write Buffer before
starting a programming operation. Within the flash memory array, each 512-byte aligned group of 512 bytes is called a Line. A
programming operation transfers volatile data from the Write Buffer to a non-volatile memory array Line. The operation is called
Write Buffer Programming.
As the device transfers each 32-byte aligned page of data that was loaded into the Write buffer to the 512-byte Flash array line,
internal logic programs an ECC Code for the Page into a portion of the memory array not visible to the host system software. The
internal logic checks the ECC information during the initial access of every array read operation. If needed, the ECC information
corrects a one bit error during the initial access time.
The Write Buffer is filled with 1’s after reset or the completion of any operation using the Write Buffer. Any locations not written to a 0
by a Write to Buffer command are by default still filled with 1’s. Any 1’s in the Write Buffer do not affect data in the memory array
during a programming operation.
As each Page of data that was loaded into the Write Buffer is transferred to a memory array Line.
Sectors may be individually protected from program and erase operations by the Advanced Sector Protection (ASP) feature set.
ASP provides several, hardware and software controlled, volatile and non-volatile, methods to select which sectors are protected
from program and erase operations.
Table 1.1
S29GL-S Address Map
Type
Count
Addresses
Address within Page
16
A3–A0
Address within Write Buffer
256
A7–A0
Page
4096
A15–A4
Write-Buffer-Line
256
A15–A8
Sector
1024 (1 Gb)
512 (512 Mb)
256 (256 Mb)
128 (128 Mb)
A
MAX
–A16
