W29C020 Datasheet, PDF (5/21 Pages) Winbond – 256K X 8 CMOS FLASH MEMORY

W29C020
Toggle Bit (DQ6)- Write Status Detection
In addition to data polling, the W29C020 provides another method for determining the end of a write
cycle. During the internal write cycle, any consecutive attempts to read DQ6 will produce alternating
0's and 1's. When the write cycle is completed, this toggling between 0's and 1's will stop. The device
is then ready for the next operation. See Toggle Bit Timing Diagram.
Product Identification
The product ID operation outputs the manufacturer code and device code. The programming
equipment automatically matches the device with its proper erase and programming algorithms.
The manufacturer and device codes can be accessed through software or by hardware operation. In
the software access mode, a six-byte command sequence can be used to access the product ID. A
read from address "00000 hex" outputs the manufacturer code "DA hex." A read from address "00001
hex" outputs the device code "45 hex." The product ID operation can be terminated by a three-byte
command sequence.
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.
TABLE OF OPERATING MODES
Operating Mode Selection
Operating Range: 0 to 70° C (Ambient Temperature), VDD = 5V ±10%, VSS = 0V, VHH = 12V
MODE
PINS
CE OE WE
ADDRESS
Read
VIL VIL VIH AIN
Write
VIL VIH VIL AIN
Standby
VIH X X X
Write Inhibit
X VIL X X
X X VIH X
Output Disable
X VIH X X
5-Volt Software Chip Erase VIL VIH VIL AIN
Product ID
VIL VIL VIH A0 = VIL; A1−A17 = VIL;
A9 = VHH
VIL VIL VIH A0 = VIH; A1−A17 = VIL;
A9 = VHH
DQ.
Dout
Din
High Z
High Z/DOUT
High Z/DOUT
High Z
DIN
Manufacturer Code DA
(Hex)
Device Code
45 (Hex)
Publication Release Date: February 1998
-5-
Revision A3