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M27C320

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

Electronic Signature.

Read Mode

The M27C320 has two organisations, Word-wide

and Byte-wide. The organisation is selected by the

the Word-wide organisation is selected and the

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

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

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-

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

Standby Mode

The M27C320 has standby mode which reduces

the supply current from 50mA to 100

µA. 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.

Table 3. Operating Modes

Table 4. Electronic Signature

Note: Outputs Q8-Q15 are set to ’0’.

Mode

E

BYTE

A9

Q0-Q7

Q8-Q14

Q15A–1

Read Word-wide

X

Data Out

Data Out

Data Out

Read Byte-wide Upper

X

Data Out

Hi-Z

Read Byte-wide Lower

X

Data Out

Hi-Z

Output Disable

X

X

Hi-Z

Hi-Z

Hi-Z

Program

X

Data In

Data In

Data In

Program Inhibit

X

Hi-Z

Hi-Z

Hi-Z

Standby

X

X

X

Hi-Z

Hi-Z

Hi-Z

Electronic Signature

Codes

Codes

Code

Identifier

A0

Q7

Q6

Q5

Q4

Q3

Q2

Q1

Q0

Hex Data

Manufacturer’s Code

001

000

00

20h

Device Code

001

100

10

32h