RapidIO Intel FPGA IP User Guide

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

5.1. Physical Layer Signals

Below tables lists the pins used by the Physical layer of the RapidIO IP core.

Table 31.  RapidIO Interface
Signal Direction Description Exported by Platform Designer (Standard)
rd Input Receive data—a unidirectional data receiver. It is connected to the td bus of the transmitting device. yes
td Output Transmit data—a unidirectional data driver. The td bus of one device is connected to the rd bus of the receiving device. yes
Table 32.  Main Clock Signals
Signal Direction Description
sysclk 32 Input Avalon® system clock
clk Input Physical layer reference clock.

In Intel® Arria® 10 and Intel® Cyclone® 10 GX variations, this clock is the reference clock for the RX CDR block in the transceiver. In other variations, this clock is also the reference clock for the TX PLL in the transceiver.

Table 33.  Global Signals
Signal Direction Description
reset_n Input Active-low system reset. In variations that implement only the Physical layer, this reset signal is associated with the reference clock. In variations with a Transport layer this reset is associated with the Avalon® system clock.

reset_n can be asserted asynchronously, but must stay asserted at least one clock cycle and must be de-asserted synchronously with the clock with which it is associated.

Intel® recommends that you apply an explicit 1 to 0 transition on the reset_n input port in simulation, to ensure that the simulation model is properly reset.

In the Platform Designer (Standard) flow, this signal is named clock_reset by default.

In Arria® V, Cyclone® V, and Stratix® V devices, the reset_n signal must be asserted synchronously with the embedded PHY IP core phy_mgmt_clk_reset signal. In addition, reset_n should not be deasserted when the Transceiver Reconfiguration Controller reconfig_busy signal is high.

rxclk Output Receive-side recovered clock. This signal is derived from the rxgxbclk clock—a clock driven by the transceiver—by division by 1 or 2, depending on the configuration of the IP core. For the frequency of this clock for each baud rate and mode.
txclk Output The internal clock of the Physical layer. This signal is derived from the txgxbclk clock—a clock driven by the transceiver—by division by 1 or 2, depending on the configuration of the IP core. For the frequency of this clock for each baud rate and mode.

This clock runs reliably only after the transceiver transmitter PLL is locked to the reference clock, which you can detect by monitoring the gxbpll_locked signal. If you use this clock to drive the Avalon® system clock, you must ensure you do not deassert reset_n before gxbpll_locked is asserted.

Table 34.  Status Packet and Error Monitoring
Output Signal Clock Domain Description Exported by Platform Designer (Standard)
packet_transmitted txclk Pulsed high for one clock cycle when a packet’s transmission completes normally. yes
packet_cancelled txclk Pulsed high for one clock cycle when a packet’s transmission is canceled by sending a stomp, a restart-from-retry, or a link-request control symbol. yes
packet_accepted rxclk Pulsed high for one clock cycle when a packet-accepted control symbol is being transmitted. yes
packet_retry rxclk Pulsed high for one clock cycle when a packet-retry control symbol is being transmitted. yes
packet_not_accepted rxclk Pulsed high for one clock cycle when a packet-not-accepted control symbol is being transmitted. yes
packet_crc_error rxclk Pulsed high for one clock cycle when a CRC error is detected in a received packet. yes
symbol_error rxclk Pulsed high for one clock cycle when a corrupted symbol is received. yes
port_initialized txclk This signal indicates that the RapidIO initialization sequence has completed successfully.

This is a level signal asserted high while the initialization state machine is in the 1X_MODE, 2X_MODE, or 4X_MODE state, as described in paragraph 4.6 of Part VI of the RapidIO Specification.

yes
port_error txclk This signal holds the value of the PORT_ERR bit of the Port 0 Error and Status CSR (offset 0x158) described in Table 6–10 on page 6–7. yes
char_err rxclk Pulsed for one clock cycle when an invalid character or a valid but illegal character is detected. yes
32 You must ensure that you drive this clock from a clock source that is running reliably when the RapidIO IP core comes out of reset.