27c256 Microchip Technology Inc., 27c256 Datasheet - Page 5

• Manufacturer Part Number: 27c256
• Description: 256k 32k X 8 Cmos Eprom
• Manufacturer: Microchip Technology Inc.

FIGURE 1-2:
TABLE 1-6:
1.2
(See Timing Diagrams and AC Characteristics)
Read Mode is accessed when:
a)
b)
Read
Program
Program Verify
Program Inhibit
Standby
Output Disable
Identity
X = Don’t Care
2004 Microchip Technology Inc.
Address
the CE pin is low to power up (enable) the chip
the OE pin is low to gate the data to the output
pins
Operation Mode
Data
V
V
CE
OE
Notes:
Read Mode
CC
PP
V
V
V
V
13.0V(2)
5.0V
6.5V(2)
5.0V
V
V
V
V
IH
IL
IH
IL
IH
IL
IH
IL
PROGRAMMING WAVEFORMS
MODES
(1)
(2)
t
V
DF
CC
and t
= 6.5 V ±0.25V, V
OE
t
t
are characteristics of the device but must be accommodated by the programmer
t
V
V
V
t
VPS
VCS
CE
V
V
V
V
AS
DS
IH
IH
IH
IL
IL
IL
IL
Data Stable
Address Stable
PP
t
PW
Program
= V
OE
V
V
V
V
V
V
X
IH
IH
IH
IL
IL
IL
H
= 13.0V ±0.25V for express algorithm
t
DH
t
OES
For Read operations, if the addresses are stable, the
address access time (t
CE to output (t
after a delay from the falling edge of OE (t
V
V
V
V
V
V
V
V
PP
CC
CC
CC
CC
H
H
H
High Z
t
(1)
OE
A9
V
CE
X
X
X
X
X
X
H
). Data is transferred to the output
Verify
ACC
Data Out Valid
) is equal to the delay from
Identity Code
27C256
O0 - O7
High Z
High Z
High Z
D
D
DS11001N-page 5
D
t
(1)
OUT
OUT
t
DF
AH
IN
OE
).