Document Number: 002-00948 Rev. *C
S29CD032J
S29CD016J
S29CL032J
S29CL016J
7.7.6 Accelerated Program Operations
Accelerated programming is enabled through the ACC function. This method is faster than the standard program command
sequences.
The device offers accelerated program operations through the ACC pin. When the system asserts V
HH
(12V) on the ACC pin, the
device automatically enters the Unlock Bypass mode. The system may then write the two-cycle Unlock Bypass program command
sequence to do accelerated programming. The device uses the higher voltage on the ACC pin to accelerate the operation. Any
sector that is being protected with the WP# pin is still protected during accelerated program. Removing V
HH
from the ACC input,
upon completion of the embedded program operation, returns the device to normal operation.
Notes
In this mode, the write protection function is bypassed unless the PPB Lock Bit = 1.
The ACC pin must not be at V
HH
for operations other than accelerated programming 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.
7.7.7 Unlock Bypass
The device features an Unlock Bypass mode to facilitate faster programming, erasing (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 for program or 6 cycles for erase. This results in faster total programming/erasing time.
Command Definitions on page 67
shows the requirements for the unlock bypass command 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 unlock 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.
7.7.8 Simultaneous Read/Write
The simultaneous read/write feature allows the host system to read data from one bank of memory 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 PPB, 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 sector being erased).
Restrictions
The Simultaneous Read/Write function is tested by executing an embedded operation in the small (busy) bank while performing
other operations in the big (non-busy) bank. However, the opposite case is neither tested nor valid. That is, it is not tested by
executing an embedded operation in the big (busy) bank while performing other operations in the small (non-busy) bank.
