Specifications GAL22LV10
fmax DESCRIPTIONS
CLK
LOGIC
ARRAY
CLK
REGISTER
LOGIC
ARRAY
t
su
tco
REGISTER
fmax with External Feedback 1/(tsu+tco)
Note: fmax with external feedback is calculated from measured
tsu and tco.
CLK
t
cf
pd
t
fmax with Internal Feedback 1/(tsu+tcf)
LOGIC
REGISTER
ARRAY
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.
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%.
11
LATTICE [ LATTICE SEMICONDUCTOR ]
