ODELAYE2 - 2024.1 English

Primitive: Output Fixed or Variable Delay Element

Introduction

This design element can be used to provide a fixed delay or an adjustable delay to the output path of the 7 series FPGA. This delay can be useful for the purpose of external data alignment, external phase offset and simultaneous switching noise (SSN) mitigation, as well as allowing for the tracking of external data alignment over process, temperature, and voltage (PVT). When used with the IDELAYCTRL component circuitry, can provide precise time increments of delay. When used in variable mode, the output path can be adjusted for increasing and decreasing amounts of delay. The ODELAYE2 is not available on the High Range (HR) banks in the 7 series devices.

Port Descriptions

Port	Direction	Width	Function
C	Input	1	All control inputs to ODELAYE2 primitive (CNTVALUEIN, RST, CE, LD, LDPIPEEN and INC) are synchronous to the clock input (C). A clock must be connected to this port when the ODELAYE2 is configured in "VARIABLE", "VAR_LOAD" or "VAR_LOAD_PIPE" mode. C can be locally inverted, and must be supplied by a global or regional clock buffer. This clock should be connected to the same clock in the SelectIO logic resources (when using OSERDESE2, C is connected to CLKDIV). If the ODELAYE2 is configured as "FIXED", connect this port to gnd.
CE	Input	1	Active-High enable increment/decrement function. If the ODELAYE2 is configured as "FIXED", connect this port to gnd.
CINVCTRL	Input	1	The CINVCTRL pin is used for dynamically switching the polarity of C pin. This is for use in applications when glitches are not an issue. When switching the polarity, do not use the ODELAYE2 control pins for two clock cycles. If the ODELAYE2 is configured as "FIXED", connect this port to gnd.
CLKIN	Input	1	Delayed Clock input into the ODELAYE2.
CNTVALUEIN<4:0>	Input	5	Counter value from FPGA logic for dynamically loadable tap value input when configured in "VAR_LOAD" or "VAR_LOAD_PIPE" modes. If the ODELAYE2 is configured as "FIXED" or "VARIABLE", connect this port to gnd.
CNTVALUEOUT<4:0>	Output	5	The CNTVALUEOUT pins are used for reporting the dynamically switching value of the delay element. CNTVALUEOUT is only available when ODELAYE2 is in "VAR_LOAD" or "VAR_LOAD_PIPE" mode.
DATAOUT	Output	1	Delayed data/clock from either the CLKIN or ODATAIN ports. DATAOUT connects to an I/O port in the case of data or back to the clocking structure in the case of a clock..
INC	Input	1	The increment/decrement is controlled by the enable signal (CE). This interface is only available when ODELAYE2 is in VARIABLE, VAR_LOAD, or VAR_LOAD_PIPE mode.
LD	Input	1	Load initial value or loaded value to the counter.
LDPIPEEN	Input	1	Enable PIPELINE register to load data from LD pins.
ODATAIN	Input	1	The ODATAIN input is the output data to be delayed driven by the OSERDESE2 or output register.
REGRST	Input	1	The REGRST signal is an active-High reset and is synchronous to the input clock signal (C). When asserted, the tap value reverts to a zero state unless LDPIPEEN is also asserted in which case the tap value results in the value on the CNTVALUEIN port.

Design Entry Method

Instantiation	Yes
Inference	No
IP Catalog	Yes
Macro support	No

Available Attributes

Attribute	Type	Allowed Values	Default	Description
CINVCTRL_SEL	STRING	"FALSE", "TRUE"	"FALSE"	Enables the CINVCTRL_SEL pin to dynamically switch the polarity of the C pin.
DELAY_SRC	STRING	"ODATAIN", "CLKIN"	"ODATAIN"	Select the data input source: "ODATAIN": ODELAYE2 chain input is ODATAIN "CLKIN": ODELAYE2 chain input is CLKIN
HIGH _PERFORMANCE _MODE	STRING	"FALSE", "TRUE"	"FALSE"	When TRUE, this attribute reduces the output jitter. When FALSE, power consumption is reduced. The difference in power consumption is quantified in the Xilinx Power Estimator tool.
ODELAY_TYPE	STRING	"FIXED", "VARIABLE", "VAR_LOAD", "VAR_LOAD_PIPE"	"FIXED"	Sets the type of tap delay line. "FIXED": Sets a static delay value "VARIABLE": Dynamically adjust (increment/decrement) delay value "VAR_LOAD": Dynamically loads tap values "VAR_LOAD_PIPE": Pipelined dynamically loadable tap values
ODELAY_VALUE	DECIMAL	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31	0	Specifies the fixed number of delay taps in fixed mode or the initial starting number of taps in "VARIABLE" mode (output path). When IDELAY_TYPE is set to "VAR_LOAD" or "VAR_LOAD_PIPE" mode, this value is ignored.
PIPE_SEL	STRING	"FALSE", "TRUE"	"FALSE"	Select pipelined mode.
REFCLK _FREQUENCY	1 significant digit FLOAT	190-210, 290-310 Mhz	200.0	Sets the tap value (in Mhz) used by the Timing Analyzer for static timing analysis and functional/timing simulation. The frequency of REFCLK must be within the given datasheet range to guarantee the tap-delay value and performance.
SIGNAL_PATTERN	STRING	"DATA", "CLOCK"	"DATA"	Causes timing analysis to account for the appropriate amount of delay-chain jitter when presented with either a "DATA" pattern with irregular transitions or a "CLOCK" pattern with a regular rise/fall pattern.

VHDL Instantiation Template

Unless they already exist, copy the following two statements and paste them before the entity declaration.

Library UNISIM;
use UNISIM.vcomponents.all;


-- ODELAYE2: Output Fixed or Variable Delay Element
--           7 Series
-- Xilinx HDL Language Template, version 2024.1

ODELAYE2_inst : ODELAYE2
generic map (
   CINVCTRL_SEL => "FALSE",          -- Enable dynamic clock inversion (FALSE, TRUE)
   DELAY_SRC => "ODATAIN",           -- Delay input (ODATAIN, CLKIN)
   HIGH_PERFORMANCE_MODE => "FALSE", -- Reduced jitter ("TRUE"), Reduced power ("FALSE")
   ODELAY_TYPE => "FIXED",           -- FIXED, VARIABLE, VAR_LOAD, VAR_LOAD_PIPE
   ODELAY_VALUE => 0,                -- Output delay tap setting (0-31)
   PIPE_SEL => "FALSE",              -- Select pipelined mode, FALSE, TRUE
   REFCLK_FREQUENCY => 200.0,        -- IDELAYCTRL clock input frequency in MHz (190.0-210.0, 290.0-310.0).
   SIGNAL_PATTERN => "DATA"          -- DATA, CLOCK input signal
)
port map (
   CNTVALUEOUT => CNTVALUEOUT, -- 5-bit output: Counter value output
   DATAOUT => DATAOUT,         -- 1-bit output: Delayed data/clock output
   C => C,                     -- 1-bit input: Clock input
   CE => CE,                   -- 1-bit input: Active high enable increment/decrement input
   CINVCTRL => CINVCTRL,       -- 1-bit input: Dynamic clock inversion input
   CLKIN => CLKIN,             -- 1-bit input: Clock delay input
   CNTVALUEIN => CNTVALUEIN,   -- 5-bit input: Counter value input
   INC => INC,                 -- 1-bit input: Increment / Decrement tap delay input
   LD => LD,                   -- 1-bit input: Loads ODELAY_VALUE tap delay in VARIABLE mode, in VAR_LOAD or
                               -- VAR_LOAD_PIPE mode, loads the value of CNTVALUEIN

   LDPIPEEN => LDPIPEEN,       -- 1-bit input: Enables the pipeline register to load data
   ODATAIN => ODATAIN,         -- 1-bit input: Output delay data input
   REGRST => REGRST            -- 1-bit input: Active-high reset tap-delay input
);

-- End of ODELAYE2_inst instantiation

Verilog Instantiation Template


// ODELAYE2: Output Fixed or Variable Delay Element
//           7 Series
// Xilinx HDL Language Template, version 2024.1

(* IODELAY_GROUP = <iodelay_group_name> *) // Specifies group name for associated IDELAYs/ODELAYs and IDELAYCTRL

ODELAYE2 #(
   .CINVCTRL_SEL("FALSE"),          // Enable dynamic clock inversion (FALSE, TRUE)
   .DELAY_SRC("ODATAIN"),           // Delay input (ODATAIN, CLKIN)
   .HIGH_PERFORMANCE_MODE("FALSE"), // Reduced jitter ("TRUE"), Reduced power ("FALSE")
   .ODELAY_TYPE("FIXED"),           // FIXED, VARIABLE, VAR_LOAD, VAR_LOAD_PIPE
   .ODELAY_VALUE(0),                // Output delay tap setting (0-31)
   .PIPE_SEL("FALSE"),              // Select pipelined mode, FALSE, TRUE
   .REFCLK_FREQUENCY(200.0),        // IDELAYCTRL clock input frequency in MHz (190.0-210.0, 290.0-310.0).
   .SIGNAL_PATTERN("DATA")          // DATA, CLOCK input signal
)
ODELAYE2_inst (
   .CNTVALUEOUT(CNTVALUEOUT), // 5-bit output: Counter value output
   .DATAOUT(DATAOUT),         // 1-bit output: Delayed data/clock output
   .C(C),                     // 1-bit input: Clock input
   .CE(CE),                   // 1-bit input: Active high enable increment/decrement input
   .CINVCTRL(CINVCTRL),       // 1-bit input: Dynamic clock inversion input
   .CLKIN(CLKIN),             // 1-bit input: Clock delay input
   .CNTVALUEIN(CNTVALUEIN),   // 5-bit input: Counter value input
   .INC(INC),                 // 1-bit input: Increment / Decrement tap delay input
   .LD(LD),                   // 1-bit input: Loads ODELAY_VALUE tap delay in VARIABLE mode, in VAR_LOAD or
                              // VAR_LOAD_PIPE mode, loads the value of CNTVALUEIN

   .LDPIPEEN(LDPIPEEN),       // 1-bit input: Enables the pipeline register to load data
   .ODATAIN(ODATAIN),         // 1-bit input: Output delay data input
   .REGRST(REGRST)            // 1-bit input: Active-high reset tap-delay input
);

// End of ODELAYE2_inst instantiation

Related Information

7 Series FPGAs SelectIO Resources User Guide (UG471)