Infineon Cypress S29GL01GS, Manual

Page: 21 / 109

Document Number: 001-98285 Rev. *R Page 20 of 108
S29GL01GS/S29GL512S
S29GL256S/S29GL128S
5. Embedded Operations
5.1 Embedded Algorithm Controller (EAC)
The EAC takes commands from the host system for programming and erasing the flash memory array and performs all the complex
operations needed to change the non-volatile memory state. This frees the host system from any need to manage the program and
erase processes.
There are four EAC operation categories:
 Standby (Read Mode)
 Address Space Switching
 Embedded Algorithms (EA)
 Advanced Sector Protection (ASP) Management
5.1.1 EAC Standby
In the standby mode current consumption is greatly reduced. The EAC enters its standby mode when no command is being
processed and no Embedded Algorithm is in progress. If the device is deselected
(CE# = High) during an Embedded Algorithm, the device still draws active current until the operation is completed (I
CC3
). I
CC4
in DC
Characteristics on page 72 represents the standby current specification when both the Host Interface and EAC are in their Standby
state.
5.1.2 Address Space Switching
Writing specific address and data sequences (command sequences) switch the memory device address space from the main flash
array to one of the Address Space Overlays (ASO).
Embedded Algorithms operate on the information visible in the currently active (entered) ASO. The system continues to have access
to the ASO until the system issues an ASO Exit command, performs a Hardware RESET, or until power is removed from the device.
An ASO Exit Command switches from an ASO back to the main flash array address space. The commands accepted when a
particular ASO is entered are listed between the ASO enter and exit commands in the command definitions table. See
Command
Summary on page 55 for address and data requirements for all command sequences.
5.1.3 Embedded Algorithms (EA)
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 Embedded Algorithm Controller (EAC). The main
algorithms perform programming and erasing of the main array data and the ASO’s. 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.