A29512 Series
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 V
ID
on
address bit A9.
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.
START
Write Program
Command
Sequence
Byte Program Command Sequence
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
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/O
7
or I/O
6
. 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/O
5
to "1", or cause the
Data
Polling algorithm to indicate the operation was
successful. However, a succeeding read will show that the
data is still "0". Only erase operations can convert a "0" to a
"1".
Embedded
Program
algorithm in
progress
Data Poll
from System
Verify Data ?
No
Yes
Increment Address
Last Address ?
Yes
Programming
Completed
Note : See the appropriate Command Definitions table for
program command sequence.
Figure 1. Program Operation
PRELIMINARY
(November, 2001, Version 0.0)
8
AMIC Technology, Inc.
AMICC [ AMIC TECHNOLOGY ]
