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September 27, 2006 S29CD-J_CL-J_00_B1
S29CD-J & S29CL-J Flash Family
33
Pr el im i n a r y
Notes:
In this mode, the write protection function is bypassed unless the
PPB Lock Bit = 1.
The ACC pin must not be at VHH for operations other than acceler-
ated programming and accelerated chip erase, or device damage
may result.
The ACC pin must not be left floating or unconnected; inconsistent
behavior of the device may result.
The Accelerated Program command is not permitted if the Secured
Silicon sector is enabled.
8.7.7
Unlock Bypass
The device features an Unlock Bypass mode to facilitate faster programming, erasing (Sector and
Chip Erase), as well as CFI commands. Once the device enters the Unlock Bypass mode, only
two write cycles are required to program or erase data, instead of the normal four cycles. This
results in faster total programming/erasing time.
sequences.
During the unlock bypass mode only the Read, Unlock Bypass Program and Unlock Bypass Reset
commands are valid. To exit the unlock bypass mode, the system must issue the two-cycle un-
lock bypass reset command sequence, which returns the device to read mode.
Notes:
1. The Unlock Bypass Command is ignored if the Secured Silicon sector is enabled.
2. Unlike the standard program or erase commands, there is no Unlock Bypass Program/Erase
Suspend or Program/Erase Resume command.
8.7.8
Simultaneous Read/Write
The simultaneous read/write feature allows the host system to read data from one bank of mem-
ory while programming or erasing in another bank of memory.
The Simultaneous Read/Write feature can be used to perform the following:
Programming in one bank, while reading in the other bank
Erasing in one bank, while reading in the other bank
Programming a PPB, while reading data from the large bank or status from the small bank
Erasing a PBB, while reading data from the large bank or status from the small bank
Any of the above situations while in the Secured Silicon Sector Mode
The Simultaneous R/W feature can not be performed during the following modes:
CFI Mode
Password Program operation
Password Verify operation
As an alternative to using the Simultaneous Read/Write feature, the user may also suspend an
erase or program operation to read in another location within the same bank (except for the sec-
tor being erased).
8.8
Write Operation Status
The device provides several bits to determine the status of a program or erase operation. The
following subsections describe the function of DQ7, DQ6, DQ2, DQ5, DQ3, and RY/BY#.