E S I
E S I
ADVANCED INFORMATION
Excel Semiconductor inc.
AUTOSELECT COMMAND
SECURITY SECTOR COMMAND
In the ES29DL320 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
41h(T),
81h(B)
Security Sector Factory
03h
82 / 02
00 / 01
Sector Group Protect Verify
(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 a bank 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 in the
other bank. The autoselect command sequence is
initiated by first writing two unlock cycles. This is
followed by a third write cycle that contains the
bank address and the autoselect command. The
bank then enters the autoselect mode. The system
may read at any address within the same bank any
number of times without initiating another autose-
lect command sequence.
Read Mode
Enter Security
Sector Command
Program, Erase or
Protection
- 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.
Exit Security
Sector Command
- A read cycle to an address containing a sector
address (SA) within the same bank, and the add-
ress 02h on A7 - A0 in word mode ( or the addre-
ss 04h on A6 - A-1 in byte mode) returns 01h if
the sector is protected, or 00h if it is unprotected.
(Refer to Table 2 for valid sector addresses).
Read Mode
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 bank was previously in Erase Suspend).
24
Rev. 0E May 25, 2006
ES29DL320
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
