93XX46X/56X/66X/76X/86X

DS21929D-page 18

© 2007 Microchip Technology Inc.

4.5

Organization (ORG)

(x16) memory organization is selected. When the ORG

organization is selected. For proper operation, ORG

must be tied to a valid logic level.

For devices without the ORG functionality, there is no

internal connection to the ORG pin. In these devices

the functionality has been set at the factory to support

a single word size.

‘A’ series devices – x8 organization

‘B’ series devices – x16 organization

4.6

Program Enable (PE)

A logic level on the PE pin will enable or disable the abil-

ity to write data to the memory array in only the 8-lead

93XX76C and 93XX86C devices. For all other devices

the PE function is not present and the PE pin is a no

connect. When driving the PE pin to a logic High, the

device can be programmed, but when the PE pin is

driven Low, programming is inhibited. This pin is used

in parallel with the EWEN/EWDS latch to protect the

memory array from inadvertent writes, as shown in

Table 4-2.

In either the 93XX76C or 93XX86C devices, the PE pin

must be tied to a specific logic level and cannot be

floated. In all other devices without the PE function, the

PE pin has no internal connections and programming is

always enabled.

TABLE 4-2:

WRITE PROTECTION SCHEME

EWEN/EWDS Latch

PE Pin*

Array WRITE

Enabled

1

Yes

Disabled

1

No

Enabled

0

No

Disabled

0

No

* PE pin level does not alter the state of the EWEN/EWDS latch.

Note:

For devices with PE functionality such as 93XX76C or 93XX86C, the write sequence requires a logic high

signal on the PE pin prior to the rising edge of clock on the last data bit.