W29GL256SH9T-TR Datasheet, PDF (32/88 Pages) Winbond – 256M-BIT 3.0-VOLT PARALLEL FLASH MEMORY WITH PAGE MODE

W29GL256S
unlock cycles, the a setup command cycle, two additional unlock write cycles and then the chip erase
command, which in turn actives the Internal Erase Algorithm.
While the Internal Erase operation is in progress, no data can be read from the device. Chip Erase
operation status can be determined by reading the Status Register or using Data Polling. Only a
Status Read, Hardware RESET or Power cycle are valid, once the chip erase operation has begun,
ignoring all other commands. When the Internal Erase Algorithm has finished, the Write State
Controller will return to the standby mode. However, in the case of a Hardware Reset or Power Cycle,
the erase operation immediately terminates and returns to read mode after a period of tRPH. In the
event the chip erase operation is terminated and to insure the integrity of the device data, the chip
erase command sequence should be reinitiated once the device has returned to an idle state.
If a sector is protected during chip erase, the Internal Erase Algorithm will ignore the protected sector
and move on to the next sector erase.
8.8.2 Sector Erase
The sector erase function erases a selected 128-kbyte sector in the main memory array. The Internal
Erase Algorithm programs and verifies the select sector prior to an electrical erase. There are no
requirements for any control signals or timing parameters during this internal operation. All locations
within the erased sector will contain an FFFFh pattern, indicating a successful sector erase. If the
sector has been protected, the sector will not be erased. Reading the Status Register or using Data
Polling can be used to determine the status of the erase operation. It takes six cycles to perform a
sector erase command sequence; writing two unlock cycles, followed by a setup command, writing
two more unlock cycles, and the sector erase command that contains the address of the desired
sector to be erased.
The Status Register Read and Erase Suspend commands are the only valid commands that can be
used after the sector erase operation has commenced, ignoring all other commands. The sector
erase operation and be terminated abruptly by a hardware reset at which time the device returns to
read mode after a period tRPH. If this is the case, the sector erase command procedure must be
redone again once the device has completed the reset operation to ensure integrity of the data.
Publication Release Date: Jul 02, 2014
Revision C
32