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Reference Design

​​SiT9120A-B120001 Differential Oscillators​

Programmable SiT9120A-B120001 differential oscillators cut lead times, lower costs, and boost reliability with 0.6 ps RMS jitter and ±20 ppm stability​

FAQ

How to instantiate differential inputs in VHDL?

For differential inputs, users can refer to the example below:COMPONENT SB_IO ISGENERIC(PIN_TYPE : std_logic_vector(5 downto 0) := "000000";IO_STANDARD: string := "SB_LVDS_INPUT");PORT(PACKAGE_PIN : in std_logic;LATCH_INPUT_VALUE : in std_logic;CLOCK_ENABLE : in std_logic;INPUT_CLK : in…

Reference Design

Single-Ended Clock from ispClock Differential Clock

Archived Design - Demonstrates I/O logic signal standard setup, PLL setup, and how to configure the I2C bus interface of the ispClock5400D device.

FAQ

Avant-G/Avant-X: What is the max peak-to-peak voltage of differential refclk for SERDES?

The max peak-to-peak input voltage of the differential reference clock for Avant-G and Avant-X is 1.15V, with a minimum = -0.3V.

FAQ

iCE40 UltraPlus: How utilize Differential Input pairs on an iCE40 device?

For iCEcube2 compatible devices (LP/HX/LM/Ultra/UltraLite/UltraPlus), the user needs to use the SB_IO primitive and override the IO_STANDARD parameter to SB_LVDS_INPUT as shown in the rudimentary example below:SB_IO SB_IO_inst ( .PACKAGE_PIN(DATA_IN), .LATCH_INPUT_VALUE(), .CLOCK_ENABLE(),…

Document

Differential Signaling

Application Note AN6019 PDF 61.2KB

FAQ

Radiant, Diamond, and ispLEVER: How should users generate the positive and negative sides for a differential signal in their design?

In Spreadsheet View, users can define the differential signal as LVDS I/O type, then assign the signal (i.e., the positive side) to a true pad. The software ispLEVER or Lattice Diamond or Lattice Radiant will automatically assign its negative side to the complementary pad. User can view the…

FAQ

How can I specify a LVPECL differential I/O in my RTL source code?

The LVPECL input standard is supported by the LVDS differential input buffer. LVPECL inputs can be implemented by instantiating a ILVDS buffer in your RTL source code. The LVPECL output standard is emulated using complementary LVCMOS outputs in conjunction with a parallel resistor across the…

FAQ

DDR/DDR2/DDR3:  How do I implement differential SSTL pads in software for my DDR memory interface design?

Differential SSTL (Stub Series Terminated Logic) I/O type is specified using a Place and Route (PAR) preference called "IOBUF". You only need to specify the positive-end of the differential SSTL pair in your RTL design. The differential I/O appears, in your RTL, like any other…

FAQ

How many additional differential pairs are there in CrossLink devices to assign the MIPI D-PHY I/Os other than the Hard D-PHY interfaces?

User can use additional D-PHY Rx interfaces available with using programmable I/Os. Below are the differential pairs available in the following packages of CrossLink devices:LIF-MD6000-6MG81I: 15 differentials pairs in bank1 and bank2.LIF-MD6000-6JMG80I: 15 differentials pairs…

FAQ

How to drive refclk of LatticeECP3 Serializer/Deserializer (SERDES) from Low Voltage Differential Signaling (LVDS) source?

You can drive LatticeECP3 SERDES refclk with the LVDS source. For the circuit arrangement, refer to TN1114, Electrical Recommendations for Lattice SERDES.http://www.latticesemi.com/view_document?document_id=20815

FAQ

iCE40: How to identify true (positive) and complementary (negative) ball functions for Low Voltage Differential Signaling (LVDS) inputs in iCE40 device?

The differential signals ending with 'B' in the Pinout file represent the positive end, and the differential signals ending with 'A' represent the negative end.For example, in the Pinout file, IOL_3A and IOL_3B are differential pins (DPIO).So, IOL_3B is considered  true…

FAQ

iCE40: Is it possible with the signal 'ENABLE_OUTPUT' of the primitive SB_IO to create a bi-directional Low Voltage Differential Signaling (LVDS) IO?

No. the signal 'ENABLE_OUTPUT' of the primitive SB_IO (IO primitive of the iCE40) cannot be used to create a bi-directional LVDS IO. One has to use two separate pairs of IOs for LVDS Tx and LVDS Rx.

FAQ

How to get IBIS model for differential LVPECL IO when the generated model from ispLEVER is a single ended model?

The low voltage positive emitter couple logic (LVPECL) interface uses two separate single ended buffers, plus on-board resistors to emulate a differential pair. The input output buffer information standard (IBIS) requires that the models be interconnected in this manner to properly model the…

Document

iCE65 Differential I/O Spreadsheet

Application Note 2.0.1 XLS 135.5KB

Document

Interfacing to ispPAC Differential Inputs

Application Note AN6026 PDF 70.2KB

IP Core

Cascaded Integrator-Comb (CIC) Filter

Widely parameterizable CIC filter that supports multiple channels with run-time programmable rates and differential delay parameters (aka Hogenauer Filter).

Reference Design

Control Link Serial Interface

Implements a low-speed serial control link using Differential Manchester code with on-chip PLL to oversample of the incoming serial data stream.

FAQ

MachXO2: I don't see Differential 3.3v CMOS inputs (LVCMOS33D) input characteristics in the MachXO2 Data Sheet.  What are its specifications?

The LVCMOS33D buffer characteristics are similar to those of the LVDS33 differential input buffer, with these key differences:Vinp/Vinm = 0v min, 3.4v max, 3.3v typ Vcm = 2.6v max, 1.65v typ Fmax = 136MHzNote: The 100ohm internal termination resistor is not available for this input…

FAQ

LatticeECP3: Is Lattice ECP3 device PCISIG (Peripheral Component Interconnect Special Interest Group) compliant in terms of Differential peak-to-peak input voltage (VRX-DIFF_P-P)?

Our Lattice ECP3 device is PCISIG compliant and passedPCISIG compliance tests at PCISIG workshop.The PCI Express Electrical and Timing Characteristics of our ECP3 datasheet says that the minimumvalue for Differential peak-to-peak input voltage (VRX-DIFF_P-P) is 340 mV and isnot in…