W19B320B Datasheet, PDF (11/51 Pages) Winbond – 32Mbit, 2.7~3.6-volt single bank CMOS flash memory

W19B320BT/B DATASHEET
The reset command may be written between the sequential cycles in an erase command sequence
before erasing begins. This resets the bank 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 bank, to which the system was writing to the 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 DQ5 goes high during a program or erase operation, writing the reset command returns the banks to
the read mode.
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 V_ID on address pin A9. The AUTOSELECT command
sequence may be written to an address within a bank that is either in the read mode. When the device
is actively programming or erasing in the other bank, 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 bank address and the AUTOSELECT command. The bank then
enters into the AUTOSELECT mode. The system may read at any address within the same bank
without initiating another AUTOSELECT command sequence:
• A read cycle at address (BA) XX00h (where BA is the bank address) returns the manufacturer code.
• A read cycle at address (BA) XX01h in word mode (or (BA) XX02h in byte mode) returns the device code.
• A read cycle to an address containing a sector address (SA) within the same bank, and the address 02h on
A7-A0 in word mode (or the address 04h on A6-A-1 in byte mode) returns 01h if the sector is
protected or 00h if it is unprotected.
To return to read mode, the system must write the reset command.
Enter Security Sector/Exit Security Sector Command Sequence
The Security Sector region provides a secured data area containing a random, sixteen-byte electronic
serial number (ESN). The system can access the Security Sector region by issuing the three-cycle
Enter Security Sector command sequence. The device continues to access the Security Sector region
until the system issues the four-cycle Exit Security Sector command sequence. The Exit Security
Sector command sequence returns the device to normal operation. See “Security Sector Flash Memory
Region” for further information.
6.2.4 Byte/Word Program Command Sequence
The device can be programmed either by word or byte, which depending on the state of the #BYTE pin.
Programming is a four-bus-cycle operation. The program command sequence is initiated by writing two
unlock write cycles, followed by the program setup command. The program address and data are
written next, which in turn initiate the Embedded Program algorithm. The device automatically provides
internally generated program pulses and verifies the programmed cell margin.
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Publication Release Date:Dec, 22, 2008
Revisionv A5