s29gl01gs Meet Spansion Inc., s29gl01gs Datasheet - Page 24

• Manufacturer Part Number: s29gl01gs
• Manufacturer: Meet Spansion Inc.

5.
5.1
5.2
24
5.1.1
5.1.2
5.1.3
Embedded Operations
Embedded Algorithm Controller (EAC)
Program and Erase Summary
EAC Standby
Address Space Switching
Embedded Algorithms (EA)
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
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
both the Host Interface and EAC are in their Standby state.
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
on page 54
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 erase 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.
Flash data bits are erased in parallel in a large group called a sector. The Erase operation places each data
bit in the sector in the logical 1 state (High). Flash data bits may be individually programmed from the erased
1 state to the programmed logical 0 (low) state. A data bit of 0 cannot be programmed back to a 1. A
succeeding read shows that the data is still 0. Only erase operations can convert a 0 to a 1. Programming the
same word location more than once with different 0 bits will result in the logical AND of the previous data and
the new data being programmed.
The duration of program and erase operations is shown in
on page
Program and erase operations may be suspended.
 An erase operation may be suspended to allow either programming or reading of another sector (not in the
erase sector) in the erase operation. No other erase operation can be started during an erase suspend.
44.
for address and data requirements for all command sequences.
CC3
). I
CC4
in
DC Characteristics on page 69
D a t a
GL-S MirrorBit
S h e e t
®
Family
( P r e l i m i n a r y )
represents the standby current specification when
Embedded Algorithm Performance Table
S29GL_128S_01GS_00_02 March 21, 2011
Command Summary