W19B(L)320ST/B
6.2.1 Reading Array Data
After device power-up, it is automatically set to reading array data. There is no commands are
required to retrieve data. After completing an Embedded Program or Embedded Erase algorithm, the
device is ready to read array data.
After the device accepts an Erase Suspend command, it enters the erase-suspend-read mode. After
this the system can read data from any non-erase-suspended sector. And then, after completing a
programming operation in the Erase Suspend mode, the system may once again read array data with
the same exception. Please refer to Erase Suspend/Erase Resume Commands section for detail
information.
The system must initiate the reset command to return the device to read (or erase-suspend-read)
mode if DQ5 goes high during an active program or erase operation; otherwise, the device is in the
autoselect mode. See Reset Command section and Requirements for Reading Array Data in the
Device Bus Operations section for more information.
6.2.2 Reset Command
The device will be to the read or erase-suspend-read mode when writing the reset command. For this
command, the address bits are Don’t Care.
The reset command may be written between the sequence cycles in an erase command sequence
before erasing begins. This resets the device to which the system was writing to the read mode. Once
erasure begins, however, the device ignores reset commands until the operation is complete.
The reset command may be written between the sequence cycles in a program command sequence
before programming begins. This resets the device, to which the system was writing to the read mode.
If the program command sequence is written to the device, in the Erase Suspend mode, writing the
reset command returns the device to the erase-suspend-read mode. When programming begins, 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. When in the autoselect mode, the reset command must be written to return to the read
mode. If the device entered into the autoselect mode while in the Erase Suspend mode, writing the
reset command returns the device to the erase-suspend-read mode.
If DQ5 goes high during a program or erase operation, writing the reset command returns the device
to the read mode (or erase-suspend-read mode if the device was in Erase Suspend).
6.2.3 Autoselect Command Sequence
The autoselect command sequence provides the host system to access the manufacturer and device
codes, and determine whether a sector is protected or not. This is an alternative method, which is
intended for PROM programmers and requires VID on address pin A9. The autoselect command
sequence may be written to an address within the device that is either in the read or erase-suspend-
read mode. When the device is actively programming or erasing, the autoselect command may not be
written.
The first writing two unlock cycles initiate the autoselect command sequence. This is followed by a
third write cycle that contains the autoselect command. The device then enters into the autoselect
mode. The system may read at any address without initiating another autoselect command sequence:
•
A read cycle at address XX00h returns the manufacturer code.
•
A read cycle at address XX01h in word mode(or XX02h in byte mode) returns the device code.
Publication Release Date: March 23, 2004
- 11 -
Revision A2
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