k8d6316u Samsung Semiconductor, Inc., k8d6316u Datasheet - Page 24

• Manufacturer Part Number: k8d6316u
• Description: 64m Bit 8m X8/4m X16 Dual Bank Nor Flash Memory
• Manufacturer: Samsung Semiconductor, Inc.

K8D6x16UTM / K8D6x16UBM
Temporary Block Group Unprotect
The protected blocks of the K8D6316U can be temporarily unprotected by applying high voltage (V
pin. In this mode, previously protected blocks can be programmed or erased with the program or erase command routines. When the
RESET pin goes high (RESET = V
, the two outermost boot blocks remain protected.
Write Protect (WP)
The WP/ACC pin has two useful functions. The one is that certain boot block is protected by the hardware method not to use V
The other is that program operation is accelerated to reduce the program time (Refer to Accelerated program Operation Paragraph).
When the WP/ACC pin is asserted at V
boot blocks independently of whether those blocks were protected or unprotected using the method described in "Block Group pro-
tection/Unprotection".
The write protected blocks can only be read. This is useful method to preserve an important program data.
The two outermost 8K byte boot blocks are the two blocks containing the lowest addresses in a bottom-boot-configured device, or
the two blocks containing the highest addresses in a top-boot-congfigured device.
(K8D6316UT : BA133 and BA134, K8D6316UB : BA0 and BA1)
When the WP/ACC pin is asserted at V
protected or unprotected. That is, block protection or unprotection for these two blocks depends on whether they were last protected
or unprotected using the method described in "Block Group protection/unprotection".
Recommend that the WP/ACC pin must not be in the state of floating or unconnected, or the device may be led to malfunction.
Secode(Security Code) Block Region
The Secode Block feature provides a Flash memory region to be stored unique and permanent identification code, that is, Electronic
Serial Number (ESN), customer code and so on. This is primarily intended for customers who wish to use an Electronic Serial Num-
ber (ESN) in the device with the ESN protected against modification. Once the Secode Block region is protected, any further modifi-
cation of that region is impossible. This ensures the security of the ESN once the product is shipped to the field.
The Secode Block is factory locked or customer lockable. Before the device is shipped, the factory locked Secode Block is written on
the special code and it is protected. The Secode Indicator bit (DQ7) is permanently fixed at "1" and it is not changed. The customer
lockable Secode Block is unprotected, therefore it is programmed and erased. The Secode Indicator bit (DQ7) of it is permanently
fixed at "0" and it is not changed. but Once it is protected, there is no procedure to unprotect and modify the Secode Block.
The Secode Block region is 64K bytes in length and is accessed through a new command sequence (see Table 8). After the system
has written the Enter Secode Block command sequence, the system may read the Secode Block region by using the same
addresses of the boot blocks (8KBx8). The K8D6316UT occupies the address of the byte mode 7F0000H to 7FFFFFH (word mode
3F8000H to 3FFFFFH) and the K8D6316UB type occupies the address of the byte mode 000000H to 00FFFFH (word mode
000000H to 007FFFH). This mode of operation continues until the system issues the Exit Secode Block command sequence, or until
power is removed from the device. On power-up, or following a hardware reset, the device reverts to read mode.
RESET
WE
CE
IH
), all the previously protected blocks will be protected again. If the WP/ACC pin is asserted at V
Figure 10. Temporary Block Group Unprotect Sequence
IL
IH
, the device can not perform program and erase operation in the two "outermost" 8K byte
, the device reverts to whether the two outermost 8K byte boot blocks were last set to be
Program & Erase Operation
at Protected Block
24
V
ID
FLASH MEMORY
ID
= 8.5V~12.5V) to the RESET
V = V
Revision 1.5
March 2005
IH
or V
IL
ID
IL
.