5962-8983902RA Datasheet, PDF (7/8 Pages) Lattice Semiconductor – High Performance E2CMOS PLD Generic Array Logic™

fmax Descriptions
CLK
Specifications GAL16V8/883
LOGIC
ARRAY
REGISTER
CLK
tsu
tco
fmax with External Feedback 1/(tsu+tco)
Note: fmax with external feedback is calculated from measured
tsu and tco.
CLK
LOGIC
ARRAY
REGISTER
tsu + th
fmax with No Feedback
Note: fmax with no feedback may be less than 1/(twh + twl). This
is to allow for a clock duty cycle of other than 50%.
LOGIC
ARRAY
REGISTER
t cf
t pd
fmax with Internal Feedback 1/(tsu+tcf)
Note: tcf is a calculated value, derived by subtracting tsu from
the period of fmax w/internal feedback (tcf = 1/fmax - tsu). The
value of tcf is used primarily when calculating the delay from
clocking a register to a combinatorial output (through registered
feedback), as shown above. For example, the timing from clock
to a combinatorial output is equal to tcf + tpd.
Switching Test Conditions
Input Pulse Levels
Input Rise and Fall Times
Input Timing Reference Levels
Output Timing Reference Levels
GND to 3.0V
3ns 10% – 90%
1.5V
1.5V
Output Load
See Figure
3-state levels are measured 0.5V from steady-state active level.
Output Load Conditions (see figure)
Test Condition
A
B Active High
Active Low
C Active High
Active Low
R1
390Ω
∞
390Ω
∞
390Ω
R2
750Ω
750Ω
750Ω
750Ω
750Ω
CL
50pF
50pF
50pF
5pF
5pF
+5V
R1
FROM OUTPUT (O/Q)
UNDER TEST
R2
TEST POINT
C _L*
*C _L INCLUDES TEST FIXTURE AND PROBE CAPACITANCE
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