W39L040 Winbond, W39L040 Datasheet - Page 6

• Manufacturer Part Number: W39L040
• Description: 512 K X 8 CMOS FLASH MEMORY
• Manufacturer: Winbond

W39L040
Algorithm. Upon executing the algorithm, the system is not required to provide further controls or
timings. The device will automatically provide adequate internally generated program pulses and verify
the programmed cell margin.
The automatic programming operation is completed when the data on DQ7 (also used as Data
Polling) is equivalent to the data written to this bit at which time the device returns to the read mode
and addresses are no longer latched (see "Hardware Sequence Flags"). Therefore, the device
requires that a valid address to the device be supplied by the system at this particular instance of time
for Data Polling operations. Data Polling must be performed at the memory location which is being
programmed.
Any commands written to the chip during the Embedded Program Algorithm will be ignored. If a
hardware reset occurs during the programming operation, the data at that particular location will be
corrupted.
Programming is allowed in any sequence and across sector boundaries. Beware that a data "0"
cannot be programmed back to a "1". Attempting to program 0 back to 1, the toggle bit will stop
toggling. Only erase operations can convert "0"s to "1"s.
Refer to the Programming Command Flow Chart using typical command strings and bus operations.
Chip Erase Command
Chip erase is a six-bus-cycle operation. There are two "unlock" write cycles, followed by writing the
"set-up" command. Two more "unlock" write cycles are asserted, followed by the chip erase
command.
Chip erase does not require the user to program the device prior to erase. Upon executing the
Embedded Erase Algorithm command sequence the device will automatically erase and verify the
entire memory for an all one data pattern. The erase is performed sequentially on each sectors at the
same time (see "Feature"). The system is not required to provide any controls or timings during these
operations.
The automatic erase begins on the rising edge of the last #WE pulse in the command sequence and
terminates when the data on DQ7 is "1" at which time the device returns to read the mode.
Refer to the Erase Command Flow Chart using typical command strings and bus operations.
Sector/Page Erase Command
Sector/page erase is a six bus cycles operation. There are two "unlock" write cycles, followed by
writing the "set-up" command. Two more "unlock" write cycles then follows by the sector erase
command. The sector/page address (any address location within the desired sector/page) is latched
on the falling edge of #WE, while the command (30H/50H) is latched on the rising edge of #WE.
Sector/page erase does not require the user to program the device prior to erase. When erasing a
sector/page or sectors/pages the remaining unselected sectors/pages are not affected. The system is
not required to provide any controls or timings during these operations.
The automatic sector/page erase begins after the erase command is completed, right from the rising
edge of the #WE pulse for the last sector/page erase command pulse and terminates when the data
on DQ7, Data Polling, is "1" at which time the device returns to the read mode. Data Polling must be
performed at an address within any of the sectors/pages being erased.
Refer to the Erase Command flow Chart using typical command strings and bus operations.
- 6 -