2-9
Architecture
LatticeECP/EC Family Data Sheet
Figure 2-8. Per Quadrant Primary Clock Selection
Figure 2-9. Per Quadrant Secondary Clock Selection
Figure 2-10. Slice Clock Selection
sysCLOCK Phase Locked Loops (PLLs)
The PLL clock input, from pin or routing, feeds into an input clock divider. There are three sources of feedback sig-
nal to the feedback divider: from CLKOP (PLL Internal), from clock net (CLKOP) or from a user clock (PIN or logic).
There is a PLL_LOCK signal to indicate that VCO has locked on to the input clock signal.
Figure 2-11 shows the
sysCLOCK PLL diagram.
The setup and hold times of the device can be improved by programming a delay in the feedback or input path of
the PLL which will advance or delay the output clock with reference to the input clock. This delay can be either pro-
4 Primary Clocks (CLK0, CLK1, CLK2, CLK3) per Quadrant
20 Primary Clock Sources: 12 PLLs + 4 PIOs + 4 Routing1
DCS
1. Smaller devices have fewer PLL related lines.
4 Secondary Clocks per Quadrant
20 Secondary Clock Feedlines : 4 Clock Input Pads + 16 Routing Signals
Primary Clock
Secondary Clock
Routing
Clock to
each slice
GND