Specifications

February 2015 IS29GL_128S_01GS_00_Rev.A GL-S MirrorBit
®
Family 25
Data Sheet
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 74 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 57 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.