E S I
E S I
Excel Semiconductor inc.
AUTOSELECT COMMAND
SECURITY SECTOR COMMAND
In the ES29LV320 device, the security sector region
(256 bytes) provides a secured data area containing
a random, sixteen-byte electronic serial num-
ber(ESN) or customer’s security codes. The secu-
rity sector region can be accessed 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.
Table 9 shows the address and data requirements
for both command sequences. Note that the accel-
erated programming function by WP#ACC and
unlock bypass mode are not available when the
device has entered the security sector. Refer to the
Fig. 7 for the security sector operation.
The autoselect command sequence allows the host
system to access the manufacturer and device
codes, and determine whether or not a sector is
protected, including information about factory-
locked or customer lockable version.
Identifier Code
Manufacturer ID
Device ID
Address
00h
Data
4Ah
01h
F6(T),
F9h(B)
Security Sector Factory Protect
Sector Group Protect Verify
03h
99 / 19
00 / 01
(SA)02h
Table 9 shows the address and data requirements.
This method is an alternative to “A9 high-voltage
method” shown in Table 2, which is intended for
PROM programmers and requires V on address
ID
pin A9. The autoselect command sequence may be
written to an address within sector that is either in
the read mode or erase-suspend-read mode. The
auto-select command may not be written while the
device is actively programming or erasing. The
autoselect command sequence is initiated by first
writing two unlock cycles. This is followed by a third
write cycle that contains the autoselect command.
The device then enters the autoselect mode. The
system may read at any address any number of
times without initiating another autoselect com-
mand sequence.
Read Mode
Enter Security
Sector Command
Program, Erase or
Protection
Once after the device enters the auto-select mode,
the manufacture ID code ( 4Ah ) can be accessed
by one of two ways. Just one read cycle ( with A6,
A1 and A0 = 0 ) can be used. Or four consecutive
read cycles ( with A6 = 1 and A1, A0 = 0 ) for con-
tinuation codes (7Fh) and then another last cycle
for the code (4Ah) (with A6, A1 and A0 = 0) can be
used for reading the manufacturer code.
Exit Security
Sector Command
Read Mode
- 4Ah (One-cycle read)
- 7Fh 7Fh 7Fh 7Fh 4Ah (Five-cycle read)
Figure 7. Security Sector Operation
The system must write the reset command to return
to the read mode (or erase-suspend-read mode if
the device was previously in Erase Suspend).
24
Rev. 0A May 25, 2006
ES29LV320E
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
