atf16v8cz ATMEL Corporation, atf16v8cz Datasheet - Page 7

• Manufacturer Part Number: atf16v8cz
• Description: Highperformance Ee Pld Atf16v8cz
• Manufacturer: ATMEL Corporation

4.5
4.6
5. Security Fuse Usage
0453H–PLD–7/05
Power-up Reset
Preload of Registered Outputs
The ATF16V8CZ’s registers are designed to reset during power-up. At a point delayed slightly
from V
put state will always be high on power-up.
This feature is critical for state machine initialization. However, due to the asynchronous nature
of reset and the uncertainty of how V
required:
The ATF16V8CZ’s registers are provided with circuitry to allow loading of each register with
either a high or a low. This feature will simplify testing since any state can be forced into the reg-
isters to control test sequencing. A JEDEC file with preload is generated when a source file with
vectors is compiled. Once downloaded, the JEDEC file preload sequence will be done automati-
cally by approved programmers.
A single fuse is provided to prevent unauthorized copying of the ATF16V8CZ fuse patterns.
Once 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.
Parameter
t
V
1. The V
2. After reset occurs, all input and feedback setup times must be met before driving the
3. The signals from which the clock is derived must remain stable during t
PR
RST
clock term high, and
CC
crossing V
CC
rise must be monotonic, from below 0.7V,
RST
Description
Power-up Reset Time
Power-up Reset Voltage
, all registers will be reset to the low state. As a result, the registered out-
CC
actually rises in the system, the following conditions are
Typ
600
3.8
ATF16V8CZ
1,000
Max
4.5
PR
.
Units
ns
V
7