Architecture
LatticeECP/EC Family Data Sheet
Lattice Semiconductor
Table 2-5. PLL Signal Descriptions
Signal
I/O
Description
CLKI
I
I
Clock input from external pin or routing
PLL feedback input from CLKOP (PLL internal), from clock net (CLKOP) or from a user clock
(PIN or logic)
CLKFB
RST
I
“1” to reset PLL
CLKOS
O
O
O
O
I
PLL output clock to clock tree (phase shifted/duty cycle changed)
PLL output clock to clock tree (No phase shift)
PLL output to clock tree through secondary clock divider
“1” indicates PLL LOCK to CLKI
CLKOP
CLKOK
LOCK
DDAMODE
DDAIZR
Dynamic Delay Enable. “1”: Pin control (dynamic), “0”: Fuse Control (static)
Dynamic Delay Zero. “1”: delay = 0, “0”: delay = on
Dynamic Delay Lag/Lead. “1”: Lead, “0”: Lag
Dynamic Delay Input
I
DDAILAG
DDAIDEL[2:0]
DDAOZR
DDAOLAG
DDAODEL[2:0]
I
I
O
O
O
Dynamic Delay Zero Output
Dynamic Delay Lag/Lead Output
Dynamic Delay Output
For more information about the PLL, please see the list of technical documentation at the end of this data sheet.
Dynamic Clock Select (DCS)
The DCS is a global clock buffer with smart multiplexer functions. It takes two independent input clock sources and
outputs a clock signal without any glitches or runt pulses. This is achieved regardless of where the select signal is
toggled. There are eight DCS blocks per device, located in pairs at the center of each side. Figure 2-13 illustrates
the DCS Block Macro.
Figure 2-13. DCS Block Primitive
CLK0
DCS
CLK1
SEL
DCSOUT
Figure 2-14 shows timing waveforms of the default DCS operating mode. The DCS block can be programmed to
other modes. For more information about the DCS, please see the list of technical documentation at the end of this
data sheet.
2-11
LATTICE [ LATTICE SEMICONDUCTOR ]
