Ultra37000 CPLD Family
0
1
TO CLOCK MUX ON
ALL INPUT MACROCELLS
O
INPUT/CLOCK PIN
C12
0
O
1
TO CLOCK MUX
IN EACH
LOGIC BLOCK
C13, C14, C15
OR C16
0
1
2
3
O
TO PIM
CLOCK POLARITY MUX
ONE PER LOGIC BLOCK
FOR EACH CLOCK INPUT
D
D
0
Q
Q
Q
FROM CLOCK
POLARITY INPUT
CLOCK PINS
1
O
2
3
C10C11
C8
C9
D
LE
Figure 4. Input/Clock Macrocell
INPUT PIN
0
1
O
TO PIM
2
3
D
D
0
Q
Q
Q
FROM CLOCK
POLARITY MUXES
1
2
3
O
C12 C13
C10 C11
D
LE
Figure 3. Input Macrocell
Timing Model
Clockin g
Each I/O and buried macrocell has access to four synchronous
clocks (CLK0, CLK1, CLK2 and CLK3) as well as an
asynchronous product term clock PTCLK. Each input
macrocell has access to all four synchronous clocks.
One of the most important features of the Ultra37000 family is
the simplicity of its timing. All delays are worst case and
system performance is unaffected by the features used. Figure
5 illustrates the true timing model for the 167-MHz devices in
high speed mode. For combinatorial paths, any input to any
output incurs a 6.5-ns worst-case delay regardless of the
amount of logic used. For synchronous systems, the input
set-up time to the output macrocells for any input is 3.5 ns and
the clock to output time is also 4.0 ns. These measurements
are for any output and synchronous clock, regardless of the
logic used.
Dedicated Inputs/Clocks
Five pins on each member of the Ultra37000 family are desig-
nated as input-only. There are two types of dedicated inputs
on Ultra37000 devices: input pins and input/clock pins.
Figure 3 illustrates the architecture for input pins. Four input
options are available for the user: combinatorial, registered,
double-registered, or latched. If a registered or latched option
is selected, any one of the input clocks can be selected for
control.
The Ultra37000 features:
• No fanout delays
• No expander delays
Figure 4 illustrates the architecture for the input/clock pins.
Like the input pins, input/clock pins can be combinatorial,
registered, double-registered, or latched. In addition, these
pins feed the clocking structures throughout the device. The
clock path at the input has user-configurable polarity.
• No dedicated vs. I/O pin delays
• No additional delay through PIM
• No penalty for using 0–16 product terms
• No added delay for steering product terms
• No added delay for sharing product terms
• No routing delays
Product Term Clocking
In addition to the four synchronous clocks, the Ultra37000
family also has a product term clock for asynchronous
clocking. Each logic block has an independent product term
clock which is available to all 16 macrocells. Each product term
clock also supports user configurable polarity selection.
• No output bypass delays
The simple timing model of the Ultra37000 family eliminates
unexpected performance penalties.
Document #: 38-03007 Rev. *D
Page 6 of 64
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