93XX46X/56X/66X/76X/86X
DS21929A-page 18
2005 Microchip Technology Inc.
4.5
Organization (ORG)
When the ORG pin is connected to VCC or Logic HI, the
(x16) memory organization is selected. When the ORG
pin is tied to VSS or Logic LO, the (x8) memory
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
ability 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
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 logic control, the PE pin must be driven high before the Chip Select enables the device and must
remain high until the Chip Select is disabled.