M27C320-80N1(1998) Ver la hoja de datos (PDF) - STMicroelectronics

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M27C320-80N1
(Rev.:1998)

32 Mbit (4Mb x8 or 2Mb x16) OTP EPROM

STMicroelectronics 

Table 3. Operating Modes

Mod e

E

Read Word-wide

VIL

Read Byte-wide Upper

VIL

Read Byte-wide Lower

VIL

Output Disable

VIL

Program

VIL Pulse

Program Inhibit

VIH

Standby

VIH

Electronic Signature

VIL

Note: X = VIH or VIL, VID = 12V ± 0.5V.

GVPP

VIL

VIL

VIL

VIH

VPP

VPP

X

VIL

Table 4. Electronic Signature

Ide ntifie r

A0

Q7

Q6

Manufacturer’s Code

VIL

0

0

Device Code

VIH

0

0

Note: Outputs Q8-Q15 are set to ’0’.

M27C320

BYTE

VIH

VIL

VIL

X

VIH

VIH

X

VIH

A9

Q0-Q7

Q8-Q14 Q15A–1

X

Data Out Data Out Data Out

X

Data Out

Hi-Z

VIH

X

Data Out

Hi-Z

VIL

X

Hi-Z

Hi-Z

Hi-Z

X

Data In

Data In

Data In

X

Hi-Z

Hi-Z

Hi-Z

X

Hi-Z

Hi-Z

Hi-Z

VID

Codes

Codes

Code

Q5

Q4

Q3

Q2

Q1

Q0 Hex Data

1

0

0

0

0

0

20h

1

1

0

0

1

0

32h

DEVICE OPERATION

The operating modes of the M27C320 are listed in

the Operating Modes Table. A single power supply

is required in the read mode. All inputs are TTL

compatible except for VPP and 12V on A9 for the

Electronic Signature.

Read Mode

The M27C320 has two organisations, Word-wide

and Byte-wide. The organisation is selected by the

signal level on the BYTE pin. When BYTE is at VIH

the Word-wide organisation is selected and the

Q15A–1 pin is used for Q15 Data Output. When

the BYTE pin is at VIL the Byte-wide organisation

is selected and the Q15A–1 pin is used for the Ad-

dress Input A–1. When the memory is logically re-

garded as 16 bit wide, but read in the Byte-wide

organisation, then with A–1 at VIL the lower 8 bits

of the 16 bit data are selected and with A–1 at VIH

the upper 8 bits of the 16 bit data are selected.

The M27C320 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 (tAVQV) is equal to the delay

from E to output (tELQV). Data is available at the

output after a delay of tGLQV from the falling edge

of G, assuming that E has been low and the ad-

dresses have been stable for at least tAVQV-tGLQV.

Standby Mode

The M27C320 has standby mode which reduces

the supply current from 50mA to 100µA. The

M27C320 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.

3/15

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