A d v a n c e I n f o r m a t i o n
Table 10. Configuration Register After Device Reset
CR15
RM
1
CR14
Reserve
0
CR13
IAD3
0
CR12
IAD2
1
CR11
IAD1
1
CR10
IAD0
1
CR9
DOC
0
CR8
Reserve
0
CR7
BS
1
CR6
CC
1
CR5
Reserve
0
CR4
Reserve
0
CR3
Reserve
0
CR2
BL2
1
CR1
BL1
0
CR0
BL0
0
Initial Access Delay Configuration
The frequency configuration informs the device of the number of clocks that must
elapse after ADV# is driven active before data will be available. This value is de-
termined by the input clock frequency.
Sector Protection
The device features several levels of sector protection, which can disable both the
program and erase operations in certain sectors or sector groups
Sector and Sector Groups
The distinction between sectors and sector groups is fundamental to sector pro-
tection. Sector are individual sectors that can be individually sector protected/
unprotected. These are the outermost 4 Kword boot sectors, that is, SA0 to SA7
and SA70 to SA77. See Tables 12 and 13.
Sector groups are a collection of three or four adjacent 32 kword sectors. For ex-
ample, sector group SG8 is comprised of sector SA8 to SA10. When any sector in
a sector group is protected/unprotected, every sector in that group is protection/
unprotected. See Tables 12 and 13.
Persistent Sector Protection
A command sector protection method that replaces the old 12 V controlled pro-
tection method.
Password Sector Protection
A highly sophisticated protection method that requires a password before
changes to certain sectors or sector groups are permitted
WP# Hardware Protection
A write protect pin that can prevent program or erase to the two outermost 8
Kbytes sectors in the 75% bank
All parts default to operate in the Persistent Sector Protection mode. The cus-
tomer must then choose if the Persistent or Password Protection method is most
desirable. There are two one-time programmable non-volatile bits that define
which sector protection method will be used. If the customer decides to continue
using the Persistent Sector Protection method, they must set the Persistent
Sector Protection Mode Locking Bit. This will permanently set the part to op-
erate only using Persistent Sector Protection. If the customer decides to use the
password method, they must set the Password Mode Locking Bit. This will
permanently set the part to operate only using password sector protection.
March 22, 2004 30606B0
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SPANSION [ SPANSION ]
