Table of operating modes – Rainbow Electronics W49F002U User Manual
Page 5
W49F002U
Publication Release Date: April 2000
- 5 -
Revision A2
Toggle Bit (DQ
6
)- Write Status Detection
In addition to data polling, the W49F002U provides another method for determining the end of a
program cycle. During the internal program or erase cycle, any consecutive attempts to read DQ
6
will
produce alternating 0's and 1's. When the program or erase cycle is completed, this toggling 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 three-byte (or JEDEC 3-byte) command sequence can be used to access
the product ID. A read from address 0000H outputs the manufacturer code DA(hex). A read from
address 0001H outputs the device code 0B(hex). The product ID operation can be terminated by a
three-byte command code sequence or an alternate one-byte command code 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.
TABLE OF OPERATING MODES
Operating Mode Selection
(V
HH
= 12V
±
5
%
)
MODE PINS
RESET
CE
OE
WE
ADDRESS
DQ.
Read V
IH
V
IL
V
IL
V
IH
A
IN
Dout
Write V
IH
V
IL
V
IH
V
IL
A
IN
Din
Standby V
IH
V
IH
X X X
High
Z
Write Inhibit
V
IH
X
V
IL
X
X
High
Z/DOUT
V
IH
X X
V
IH
X
High
Z/DOUT
Output Disable
V
IH
X
V
IH
X X
High
Z
Reset Mode
V
IL
X X X
X
High
Z
Product ID
V
IH
V
IL
V
IL
V
IH
A0 = V
IL
; A1
−
A17 = V
IL
;
A9 = V
HH
Manufacturer Code DA (Hex)
V
IH
V
IL
V
IL
V
IH
A0 = V
IH
; A1
−
A17 = V
IL
;
A9 = V
HH
Device Code 0B (Hex)