Stratix® V Device Handbook: Volume 1: Device Interfaces and Integration

ID 683665
Date 10/18/2023
Public
Document Table of Contents

4.2.8.7. Multiple PLLs in Normal Mode and Source Synchronous Mode

Normal and source synchronous compensation feedback mode require GCLK or RCLK feedback path to achieve the required phase relationship. Source synchronous mode for LVDS compensation does not require the GCLK or RCLK feedback path.

The GCLK or RCLK network feedback paths are fewer than the PLLs available on the device. You cannot implement the compensation mode that requires GCLK or RCLK feedback path on all the PLLs available on the device simultaneously.

Consider the following guidelines when implementing normal compensation or source synchronous compensation mode on multiple PLLs for the device:

  • You can implement normal compensation or source synchronous compensation mode on all the center PLLs simultaneously.
  • The Stratix® V device has two middle PLLs on the left and right side of the device. All PLLs that reside on each side of the device can be divided equally into 2 groups as shown in the following figure.
Figure 82. Example of the PLL Grouping for Stratix® V GX A5 and A7 Devices, and Stratix® V GT C5 and C7 Devices This figure represents the top view of the silicon die that corresponds to a reverse view of the device package.


From the PLL grouping example, the PLLs can be divided into 4 different sections (upper left, lower left, upper right, and lower right). The PLLs in each of these sections can be further divided into first and second group. The first group consists of the 2 corner PLLs and one middle PLL located in each section. The remaining PLLs in the same section are grouped into the second group. For each section, you can use up to 3 PLLs to implement source synchronous or normal compensation mode in the following combinations:

  • Any of the 3 PLLs in the first group
  • Any of the 2 PLLs in the first group and 1 PLL in the second group
Table 27.  Example of the PLL Grouping for Stratix® V GX A5 and A7 Devices, and Stratix® V GT C5 and C7 Devices
PLL Section PLL Location
First Group Second Group
Upper left FRACTIONALPLL_X0_Y122, FRACTIONALPLL_X0_Y113, FRACTIONALPLL_X0_Y66 FRACTIONALPLL_X0_Y100, FRACTIONALPLL_X0_Y91, FRACTIONALPLL_X0_Y75
Lower left FRACTIONALPLL_X0_Y53, FRACTIONALPLL_X0_Y10, FRACTIONALPLL_X0_Y1 FRACTIONALPLL_X0_Y44, FRACTIONALPLL_X0_Y29, FRACTIONALPLL_X0_Y20
Upper right FRACTIONALPLL_X210_Y122, FRACTIONALPLL_X210_Y113, FRACTIONALPLL_X210_Y66 FRACTIONALPLL_X210_Y100, FRACTIONALPLL_X210_Y91, FRACTIONALPLL_X210_Y75
Lower right FRACTIONALPLL_X210_Y53, FRACTIONALPLL_X210_Y10, FRACTIONALPLL_X210_Y1 FRACTIONALPLL_X210_Y44, FRACTIONALPLL_X210_Y29, FRACTIONALPLL_X210_Y20