M27C320 datasheet(11/15 Pages) STMICROELECTRONICS

11 / 15 page

11/15

M27C320

On-Board Programming

The M27C320 can be directly programmed in the

application circuit. See the relevant Application

Note AN620.

Electronic Signature

The Electronic Signature (ES) mode allows the

reading out of a binary code from an EPROM that

will identify its manufacturer and type. This mode

is intended for use by programming equipment to

automatically match the device to be programmed

with its corresponding programming algorithm.

The ES mode is functional in the 25

°C ± 5°C am-

bient temperature range that is required when pro-

gramming the M27C320. To activate the ES

mode, the programming equipment must force

11.5V to 12.5V on address line A9 of the

M27C320, with VPP=VCC=5V. Two identifier bytes

may then be sequenced from the device outputs

by toggling address line A0 from VIL to VIH. All oth-

er address lines must be held at VIL during Elec-

tronic Signature mode.

Byte 0 (A0=VIL) represents the manufacturer code

and byte 1 (A0=VIH) the device identifier code. For

the STMicroelectronics M27C320, these two iden-

tifier bytes are given in Table 4 and can be read-

out on outputs Q0 to Q7.

M27C320 Datasheet(PDF) 11 Page - STMicroelectronics