M27C400-100B6TR STMICROELECTRONICS [STMicroelectronics], M27C400-100B6TR Datasheet - Page 2

• Manufacturer Part Number: M27C400-100B6TR
• Description: 4 Mbit 512Kb x8 or 256Kb x16 UV EPROM and OTP EPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M27C400
Figure 2. DIP Connections
DEVICE OPERATION
The operating modes of the M27C400 are listed in
the Operating Modes Table. A single power supply
is required in the read mode. All inputs are TTL
compatible except for V
Electronic Signature.
Read Mode
The M27C400 has two organisations, Word-wide
and Byte-wide. The organisation is selected by the
signal level on the BYTEV
is at V
and the Q15A–1 pin is used for Q15 Data Output.
When the BYTEV
ganisation is selected and the Q15A–1 pin is used
for the Address Input A–1. When the memory is
2/14
IH
the Word-wide organisation is selected
V SS
Q10
Q11
A17
Q0
Q8
Q1
Q9
Q2
Q3
A7
A6
A5
A4
A3
A2
A1
A0
G
E
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PP
M27C400
pin is at V
PP
PP
and 12V on A9 for the
AI01635
pin. When BYTEV
IL
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
the Byte-wide or-
A8
A9
A10
A11
A12
A13
A14
A15
A16
BYTEV PP
V SS
Q15A–1
Q7
Q14
Q6
Q13
Q5
Q12
Q4
V CC
PP
Table 1. Signal Names
logically regarded as 16 bit wide, but read in the
Byte-wide organisation, then with A–1 at V
lower 8 bits of the 16 bit data are selected and with
A–1 at V
selected.
The M27C400 has two control functions, both of
which must be logically active in order to obtain
data at the outputs. In addition the Word-wide or
Byte- wide organisation must be selected.
Chip Enable (E) is the power control and should be
used for device selection. Output Enable (G) is the
output control and should be used to gate data to
the output pins independent of device selection.
Assuming that the addresses are stable, the ad-
dress access time (t
from E to output (t
output after a delay of t
of G, assuming that E has been low and the ad-
dresses have been stable for at least t
Standby Mode
The M27C400 has a standby mode which reduces
the supply current from 50mA to 100µA. The
M27C400 is placed in the standby mode by apply-
ing a CMOS high signal to the E input. When in the
standby mode, the outputs are in a high imped-
ance state, independent of the G input.
A0-A17
Q0-Q7
Q8-Q14
Q15A–1
E
G
BYTEV
V
V
CC
SS
PP
IH
the upper 8 bits of the 16 bit data are
ELQV
Address Inputs
Data Outputs
Data Outputs
Data Output / Address Input
Chip Enable
Output Enable
Byte Mode / Program Supply
Supply Voltage
Ground
AVQV
GLQV
). Data is available at the
) is equal to the delay
from the falling edge
AVQV
-t
GLQV
IL
the
.