M27C800 datasheet(4/18 Pages) STMICROELECTRONICS

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M27C800

4/18

DEVICE OPERATION

The operating modes of the M27C800 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 M27C800 has two organisations, Word-wide

and Byte-wide. The organisation is selected by the

signal level on the BYTEVPP pin. When BYTEVPP

is at VIH the Word-wide organisation is selected

and the Q15A–1 pin is used for Q15 Data Output.

When the BYTEVPP pin is at VIL the Byte-wide or-

ganisation is selected and the Q15A–1 pin is used

for the Address Input A–1. When the memory is

logically regarded 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 M27C800 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)isthe

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.

Table 5. AC Measurement Conditions

High Speed

Standard

Input Rise and Fall Times

≤ 10ns

≤ 20ns

Input Pulse Voltages

0 to 3V

0.4V to 2.4V

Input and Output Timing Ref. Voltages

1.5V

0.8V and 2V

Figure 3. AC Testing Input Output Waveform

AI01822

High Speed

1.5V

2.4V

Standard

0.4V

2.0V

0.8V

Figure 4. AC Testing Load Circuit

AI01823B

1.3V

OUT

CL = 30pF for High Speed

CL = 100pF for Standard

CL includes JIG capacitance

3.3k

Ω

1N914

DEVICE

UNDER

TEST

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