RapidIO Intel FPGA IP User Guide

ID 683884
Date 9/15/2021
Public
Document Table of Contents

4.2.2.3. Reset Requirements for Arria® V, Cyclone® V, and Stratix® V Variations

Arria® V, Cyclone® V, and Stratix® V variations have the following additional constraints:
  • The Custom PHY IP core phy_mgmt_clk_reset signal and the RapidIO IP core reset_n signal must be driven from the same source, with the caveat that the phy_mgmt_clk_reset signal is active high and the reset_n signal is active low. The two reset signals must be asserted synchronously, but deasserted each according to its corresponding clock. The following figure shows a circuit that ensures the requirements for these two reset signals are met.
  • You must ensure that the system does not deassert reset_n and phy_mgmt_clk_reset when the Transceiver Reconfiguration Controller reconfig_busy signal is asserted. The RapidIO IP core must remain in reset until the Transceiver Reconfiguration Controller is available.

The assertion of reset_n causes the whole IP core to reset. In Arria V, Cyclone® V, and Stratix® V devices, the requirement that phy_mgmt_clk_reset be asserted with reset_n ensures that the PHY IP core resets with the RapidIO IP core. While the module is held in reset, the Avalon® -MM waitrequest outputs are driven high and all other outputs are driven low. When the module comes out of the reset state, all buffers are empty.

In Arria® V, Cyclone® V, and Stratix® V devices, phy_mgmt_clk_reset must be asserted with reset_n. However, each signal is deasserted synchronously with its corresponding clock.

Figure 11. Circuit to Also Ensure Synchronous Assertion of phy_mgmt_clk_reset with reset_n

In systems generated by Platform Designer (Standard), this circuit is generated automatically. However, if your Arria® V, Cyclone® V, or Stratix® V RapidIO IP core variation is not generated by Platform Designer (Standard), you must implement logic to ensure that reset_n and phy_mgmt_clk_reset are driven from the same source, and that each meets the minimal hold time and synchronous deassertion requirements.