Specifications GAL26CV12
Power-Up Reset
Vcc (min.)
Vcc
t
su
CLK
t
wl
t
pr
Internal Register
Reset to Logic "0"
INTERNAL REGISTER
Q - OUTPUT
ACTIVE LOW
OUTPUT REGISTER
Device Pin
Reset to Logic "1"
Device Pin
Reset to Logic "0"
ACTIVE HIGH
OUTPUT REGISTER
provide a valid power-up reset of the device. First, the VCC rise must
be monotonic. Second, the clock input must be at static TTL level
as shown in the diagram during power up. The registers will reset
within a maximum of tpr time. As in normal system operation, avoid
clocking the device until all input and feedback path setup times
have been met. The clock must also meet the minimum pulse width
requirements.
Circuitry within the GAL26CV12 provides a reset signal to all reg-
isters during power-up. All internal registers will have their Q outputs
set low after a specified time (tpr, 1µs MAX). As a result, the state
on the registered output pins (if they are enabled) will be either high
or low on power-up, depending on the programmed polarity of the
output pins. This feature can greatly simplify state machine design
by providing a known state on power-up. Because of the asynchro-
nous nature of system power-up, some conditions must be met to
Input/Output Equivalent Schematics
PIN
PIN
Feedback
Vcc
Active Pull-up
Circuit
Active Pull-up
Circuit
(Vref Typical = 3.2V)
(Vref Typical = 3.2V)
Vcc
Tri-State
Control
Vref
Vcc
Vcc
Vref
ESD
Protection
Circuit
Data
Output
PIN
PIN
ESD
Protection
Circuit
Feedback
(To Input Buffer)
Typical Input
Typical Output
13
LATTICE [ LATTICE SEMICONDUCTOR ]
