A29040B Series
system may once again read array data with the same
exception. See "Erase Suspend/Erase Resume Commands"
for more information on this mode.
The system must issue the reset command to re-enable the
device for reading array data if I/O5 goes high, or while in the
autoselect mode. See the "Reset Command" section, next.
See also "Requirements for Reading Array Data" in the
"Device Bus Operations" section for more information. The
Read Operations table provides the read parameters, and
Read Operation Timings diagram shows the timing diagram.
required to provide further controls or timings. The device
automatically provides internally generated program pulses
and verify the programmed cell margin. The Command
Definitions table shows the address and data requirements
for the byte program command sequence.
When the Embedded Program algorithm is complete, the
device then returns to reading array data and addresses are
no longer latched. The system can determine the status of
the program operation by using I/O7 or I/O6. See "Write
Operation Status" for information on these status bits.
Any commands written to the device during the Embedded
Program Algorithm are ignored. Programming is allowed in
any sequence and across sector boundaries. A bit cannot be
programmed from a "0" back to a "1 ". Attempting to do so
may halt the operation and set I/O5 to "1", or cause the
Reset Command
Writing the reset command to the device resets the device to
reading array data. Address bits are don't care for this
command. The reset command may be written between the
sequence cycles in an erase command sequence before
erasing begins. This resets the device to reading array data.
Once erasure begins, however, the device ignores reset
commands until the operation is complete.
Polling algorithm to indicate the operation was
Data
successful. However, a succeeding read will show that the
data is still "0". Only erase operations can convert a "0" to a
"1".
The reset command may be written between the sequence
cycles in
a
program command sequence before
START
programming begins. This resets the device to reading array
data (also applies to programming in Erase Suspend mode).
Once programming begins, however, the device ignores
reset commands until the operation is complete.
The reset command may be written between the sequence
cycles in an autoselect command sequence. Once in the
autoselect mode, the reset command must be written to
return to reading array data (also applies to autoselect
during Erase Suspend).
Write Program
Command
Sequence
If I/O5 goes high during a program or erase operation, writing
the reset command returns the device to reading array data
(also applies during Erase Suspend).
Data Poll
from System
Embedded
Program
algorithm in
progress
Autoselect Command Sequence
The autoselect command sequence allows the host system
to access the manufacturer and devices codes, and
determine whether or not a sector is protected. The
Command Definitions table shows the address and data
requirements. This method is an alternative to that shown in
the Autoselect Codes (High Voltage Method) table, which is
intended for PROM programmers and requires VID on
address bit A9.
Verify Data ?
No
Yes
The autoselect command sequence is initiated by writing two
unlock cycles, followed by the autoselect command. The
device then enters the autoselect mode, and the system
may read at any address any number of times, without
initiating another command sequence.
A read cycle at address XX00h retrieves the manufacturer
code and another read cycle at XX03h retrieves the
continuation code. A read cycle at address XX01h returns
the device code. A read cycle containing a sector address
(SA) and the address 02h in returns 01h if that sector is
protected, or 00h if it is unprotected. Refer to the Sector
Address tables for valid sector addresses.
Increment Address
Last Address ?
Yes
Programming
Completed
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Note : See the appropriate Command Definitions table for
program command sequence.
Byte Program Command Sequence
Figure 1. Program Operation
Programming is a four-bus-cycle operation. The program
command sequence is initiated by writing two unlock write
cycles, followed by the program set-up command. The
program address and data are written next, which in turn
initiate the Embedded Program algorithm. The system is not
PRELIMINARY
(December, 2004, Version 0.2)
7
AMIC Technology, Corp.
AMICC [ AMIC TECHNOLOGY ]
