Rev 1.3 / Jun. 2006 14
HY27US(08/16)121A Series
HY27SS(08/16)121A Series
512Mbit (64Mx8bit / 32Mx16bit) NAND Flash
3. DEVICE OPERATION
3.1 Page Read.
Upon initial device power up, the device def aults to Read1 mode. Th is operation is also initiated by writing 00h to the
command register along with followed by the four address input cycles. Once the command is latched, it does not
need to be written for the following page read operation.
Three types of operations are available: random read, serial page read and sequential row read.
The random read mode is enabled when the page address is changed. The 528 bytes (x8 device) or 264 word (x16
device) of data within the selected page are transferred to the data registers in less than access random read time tR
(12us, 3.3V device). The system controller can detect the completion of this data transfer tR (12us, 3.3V device) by
analyzing the output of R/B pin. Once the data in a page is loaded into the registers, they may be read out in 50ns
cycle time by sequentially puls ing RE. High to low transitions of the RE clock output the data stating from the selected
column address up to the last column address.
After the data of last column address is clocked out, the next page is automatically selected for sequential row read.
Waiting tR again allows reading the selected page. The sequential row read operation is terminated by bringing CE
high.
The way the Read1 and R e ad2 comma nds work is like a pointer set to either the main ar ea or the spar e area. Writing
the R ead2 comm and use r may selectively access the s par e a rea of bytes 512 to 527. Addresses A0 to A3 set the start-
ing address of the spar e area while addr esses A4 to A7 are ignore d. Unless the oper ation is aborted, the p age addr ess
is automatically incremented for sequential row
Read as in Read1 operation and spare sixteen bytes of each page may be sequentially read. The Read1 command
(00h/01h) is needed to move the pointer back to the main area. Figure_11 to 13 show typical sequence and timings
for each read operation.
Devices with automatic read of page0 at power up can be provided on request.
3.2 Page Program.
The device is progr am med basically on a page ba sis, but it does allow multiple partial page progr amming of a b yte or
consecutive bytes up to 528 (x8 device), in a single page program cycle. The number of consecutive partial page pro-
gramming operations within the same page without an intervening erase operation must not exceed 1 for main array
and 2 for spar e arr ay. The addressing may be done in any r andom order in a block. A pa ge progr am cycle consists of a
serial data loading period in which up to 528 bytes (x8 device) or 264 word (x16 device) of data may be loaded into
the page register, followed by a non-volatile programming period where the loaded data is programmed into the
appropriate cell. Serial data loading can be started from 2nd half arr ay by mo ving pointer. About the pointer operation,
please refer to Figure_29.
The data-loading sequence begins by inputting the Serial Data Input command (80h), followed by the four address
input cycles and then serial data loading. The P age Prog r am confirm command (10h) starts the progr amming process.
Writing 10h alone without previo usly entering the serial data will not initiate the programming pr ocess. The internal P/
E/R Controller automatically exec utes the algorithms and timings necessary f or progra m and verify, thereby freeing the
system controller for other tasks. Once the program process starts, the Read Status Register command may be
entered, with RE and CE low , to read the status r egister. The system controller can detect the completion of a program
cycle by monitoring the R/B output, or the Status bit (I/O 6) of the Status Register. Only the Read Status command
and Reset command are valid while progr amming is in progress. When the P age Progra m is complete, the Write Status
Bit (I/O 0) may be checked Figure_17
The internal write verify detects only errors for "1"s that are not successfully programmed to "0"s. The command reg-
ister remains in Read Status command mode until another valid command is written to the command register.