LFXP3E-3QN208C Lattice, LFXP3E-3QN208C Datasheet - Page 12

• Manufacturer Part Number: LFXP3E-3QN208C
• Description: IC FPGA 3.1KLUTS 208PQFP
• Manufacturer: Lattice

Specifications of LFXP3E-3QN208C

• Number Of Logic Elements/cells: *
• Number Of Labs/clbs: *
• Total Ram Bits: *
• Number Of I /o: *
• Number Of Gates: *
• Voltage - Supply: *
• Mounting Type: *
• Operating Temperature: *
• Package / Case: *
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Architecture
Lattice Semiconductor
LatticeXP Family Data Sheet
Figure 2-8. Per Quadrant Secondary Clock Selection
20 Secondary Clock Feedlines : 4 Clock Input Pads + 16 Routing Signals
4 Secondary Clocks per Quadrant
Figure 2-9. Slice Clock Selection
Primary Clock
Secondary Clock
Clock to Each Slice
Routing
GND
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-
nals to the feedback divider: from CLKOP (PLL internal), from clock net (CLKOP or CLKOS) 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 2-10
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-
grammed during configuration or can be adjusted dynamically. In dynamic mode, the PLL may lose lock after
adjustment and not relock until the t
parameter has been satisfied. Additionally, the phase and duty cycle block
LOCK
allows the user to adjust the phase and duty cycle of the CLKOS output.
The sysCLOCK PLLs provide the ability to synthesize clock frequencies. Each PLL has four dividers associated
with it: input clock divider, feedback divider, post scalar divider and secondary clock divider. The input clock divider
is used to divide the input clock signal, while the feedback divider is used to multiply the input clock signal. The post
scalar divider allows the VCO to operate at higher frequencies than the clock output, thereby increasing the fre-
quency range. The secondary divider is used to derive lower frequency outputs.
2-9