7

0779M–PLD–7/10

Atmel ATF22LV10C(Q)Z

5.

Electronic Signature Word

There are 64-bits of programmable memory that are always available to the user, even if the device is secured.

These bits can be used for user-specific data.

6.

Security Fuse Usage

programmed, fuse verify and preload are inhibited. However, the 64-bit User Signature remains accessible.

The security fuse should be programmed last, as its effect is immediate.

7.

Programming/Erasing

Programming/erasing is performed using standard PLD programmers. See CMOS PLD Programming

Hardware and Software Support for information on software/ programming.

Table 7-1.

Programming/Erasing

8.

Input and I/O Pin Keepers

All ATF22LV10CZ/CQZ family members have internal input and I/O pin-keeper circuits. Therefore, whenever

inputs or I/Os are not being driven externally, they will maintain their last driven state. This ensures that all logic

array inputs and device outputs are at known states. These are relatively weak active circuits that can be easily

overridden by TTL-compatible drivers (see input and I/O diagrams below).

Figure 8-1.

Input Diagram

Parameter

Description

Typ

Max

Units

T

PR

Power-up

Reset Time

600

1000

ns

V

RST

Power-up

Reset Voltage

2.3

2.7

V

100K

V

CC

ESD

PROTECTION

CIRCUIT

INPUT