K5A3X40YTC Datasheet, PDF (19/45 Pages) Samsung semiconductor – Multi-Chip Package MEMORY 32M Bit (4Mx8/2Mx16) Dual Bank NOR Flash Memory / 4M(512Kx8/256Kx16) Full CMOS SRAM

K5A3x40YT(B)C
Preliminary
MCP MEMORY
Write Protect (WP)
The WP/ACC ball has two useful functions. The one is that certain boot block is protected by the hardware method not to use VID.
The other is that program operation is accelerated to reduce the program time (Refer to Accelerated program Operation Paragraph).
When the WP/ACC ball is asserted at VIL, the device can not perform program and erase operation in the two "outermost" 8K byte
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.
(K5A3240YT/K5A3340YT : BA69 and BA70, K5A3240YB/K5A3340YB : BA0 and BA1)
When the WP/ACC ball is asserted at VIH, the device reverts to whether the two outermost 8K byte boot blocks were last set to be
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 ball 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 5). 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 K5A3240YT/K5A3340YT occupies the address of the byte mode 3F0000H to 3FFFFFH
(word mode 1F8000H to 1FFFFFH) and the K5A3240YB/K5A3340YB 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 com-
mand sequence, or until power is removed from the device. On power-up, or following a hardware reset, the device reverts to read
mode.
Accelerated Program Operation
Accelerated program operation reduces the program time. This is one of two functions provided by the WP/ACC ball. When the WP/
ACC ball is asserted as VHH, the device automatically enters the aforementioned Unlock Bypass mode, temporarily unprotecting any
protected blocks, and reduces the program operation time. The system would use a two-cycle program command sequence as
required by the Unlock Bypass mode. Removing VHH from the WP/ACC ball returns the device to normal operation. Recommend
that the WP/ACC ball must not be asserted at VHH except accelerated program operation, or the device may be damaged. In
addition, the WP/ACC ball must not be in the state of floating or unconnected, otherwise the device may be led to malfunc-
tion.
Software Reset
The reset command provides that the device is reseted to read mode or erase-suspend-read mode. The addresses are in Don't Care
state. The reset command is vaild between the sequence cycles in an erase command sequence before erasing begins, or in a pro-
gram command sequence before programming begins. This resets the bank in which was operating to read mode. if the device is be
erasing or programming, the reset command is invalid until the operation is completed. Also, the reset command is valid between the
sequence cycles in an autoselect command sequence. In the autoselect mode, the reset command returns the bank to read mode. If
a bank entered the autoselect mode in the Erase Suspend mode, the reset command returns the bank to erase-suspend-read mode.
If DQ5 is high on erase or program operation, the reset command return the bank to read mode or erase-suspend-read mode if the
bank was in the Erase Suspend state.
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Revision 0.0
November 2002