Preliminary W49L102

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to provide any control or timing during this operation. The device will automatically return to normal

read mode after the erase operation completed. Data polling and/or Toggle Bits can be used to detect

end of erase cycle.

Program Operation

The W49L102 is programmed on a word-by-word basis. Program operation can only change logical

data "1" to logical data "0" The erase operation (changed entire data in main memory and/or boot

block from "0" to "1" is needed before programming.

The program operation is initiated by a 4-word command cycle (see Command Codes for Word

Programming). The device will interally enter the program operation immediately after the word-

program command is entered. The internal program timer will automatically time-out (50

µS max. -

detect end of program cycle.

Hardware Data Protection

The integrity of the data stored in the W49L102 is also hardware protected in the following ways:

(1) Noise/Glitch Protection: A WE pulse of less than 15 nS in duration will not initiate a write cycle.

1.8V typical.

(3) Write Inhibit Mode: Forcing OE low, CE high, or WE high will inhibit the write operation. This

prevents inadvertent writes during power-up or power-down periods.

out 10 mS before any write (erase/program) operation.

The W49L102 includes a data polling feature to indicate the end of a program or erase cycle. When

word loaded will receive the complement of the true data. Once the program or erase cycle is

the erase cycle, and become logical "1" or true data when the erase cycle has been completed.

In addition to data polling, the W49L102 provides another method for determining the end of a

between 0's and 1's will stop. The device is then ready for the next operation.

Product Identification

The product ID operation outputs the manufacturer code and device code. Programming equipment

automatically matches the device with its proper erase and programming algorithms.

The manufacturer and device codes can be accessed by software or hardware operation. In the

software access mode, a six-word (or JEDEC 3-word) command sequence can be used to access the

product ID. A read from address 0000H outputs the manufacturer code (00DAh). A read from address

0001H outputs the device code (00BFh). The product ID operation can be terminated by a three-word

command sequence or an altenate one-word command sequence (see Command Definition table).

In the hardware access mode, access to the product ID is activated by forcing CE and OE low, WE

high, and raising A9 to 12 volts.