Primitive: Dedicated Double Data Rate (DDR) Input Register
- PRIMITIVE_GROUP: REGISTER
- PRIMITIVE_SUBGROUP: DDR
Introduction
The IDDRE1 I/O Logic primitive in Versal devices is a dedicated input register designed to receive external double data rate (DDR) signals into Xilinx devices. The IDDRE1 is available with modes that present the data to the device fabric at the time and clock edge they are captured, or on the same clock edge. This feature allows you to avoid additional timing complexities and resource usage.
Port Descriptions
Port | Direction | Width | Function |
---|---|---|---|
C | Input | 1 | The high-speed clock input (C) is used to clock in the input serial data stream. |
CB | Input | 1 | The inverted high-speed clock input. |
D | Input | 1 | The serial input data port (D) is the serial (high-speed) data input port of the ISERDESE3. This port accepts data from the IOB or device Fabric. |
Q1 | Output | 1 | Registered parallel output 1. |
Q2 | Output | 1 | Registered parallel output 2. |
R | Input | 1 | Active-High Asynchronous Reset. |
Design Entry Method
Instantiation | Yes |
Inference | No |
IP and IP Integrator Catalog | Yes |
Available Attributes
Attribute | Type | Allowed Values | Default | Description |
---|---|---|---|---|
DDR_CLK_EDGE | STRING | "OPPOSITE_EDGE", "SAME_EDGE", "SAME_EDGE_PIPELINED" | "OPPOSITE_EDGE" | Sets the IDDRE1 mode of operation with respect to clock edge.
|
IS_CB_INVERTED | BINARY | 1'b0 to 1'b1 | 1'b0 | Specifies whether the clock CB pin is active-High or active-Low. |
IS_C_INVERTED | BINARY | 1'b0 to 1'b1 | 1'b0 | Specifies whether the clock C pin is active-High or active-Low. |
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;
-- IDDRE1: Dedicated Double Data Rate (DDR) Input Register
-- Versal Prime series
-- Xilinx HDL Language Template, version 2021.1
IDDRE1_inst : IDDRE1
generic map (
DDR_CLK_EDGE => "OPPOSITE_EDGE", -- IDDRE1 mode (OPPOSITE_EDGE, SAME_EDGE, SAME_EDGE_PIPELINED)
IS_CB_INVERTED => '0', -- Optional inversion for CB
IS_C_INVERTED => '0' -- Optional inversion for C
)
port map (
Q1 => Q1, -- 1-bit output: Registered parallel output 1
Q2 => Q2, -- 1-bit output: Registered parallel output 2
C => C, -- 1-bit input: High-speed clock
CB => CB, -- 1-bit input: Inversion of High-speed clock C
D => D, -- 1-bit input: Serial Data Input
R => R -- 1-bit input: Active-High Async Reset
);
-- End of IDDRE1_inst instantiation
Verilog Instantiation Template
// IDDRE1: Dedicated Double Data Rate (DDR) Input Register
// Versal Prime series
// Xilinx HDL Language Template, version 2021.1
IDDRE1 #(
.DDR_CLK_EDGE("OPPOSITE_EDGE"), // IDDRE1 mode (OPPOSITE_EDGE, SAME_EDGE, SAME_EDGE_PIPELINED)
.IS_CB_INVERTED(1'b0), // Optional inversion for CB
.IS_C_INVERTED(1'b0) // Optional inversion for C
)
IDDRE1_inst (
.Q1(Q1), // 1-bit output: Registered parallel output 1
.Q2(Q2), // 1-bit output: Registered parallel output 2
.C(C), // 1-bit input: High-speed clock
.CB(CB), // 1-bit input: Inversion of High-speed clock C
.D(D), // 1-bit input: Serial Data Input
.R(R) // 1-bit input: Active-High Async Reset
);
// End of IDDRE1_inst instantiation
Related Information
- Versal ACAP SelectIO Resources Architecture Manual (AM010)