Interrupt Status Register - Interrupt Status Register - 7.2 English - PG138

AXI 1G/2.5G Ethernet Subsystem Product Guide (PG138)

Document_ID
PG138
Release_Date
2024-06-05
Version
7.2 English

The Interrupt Status (IS) register is shown in Figure 1. This register combined with the IE, IP, MIS, and MIE registers define the interrupt interface of the subsystem. The Interrupt Status register uses one bit to represent each internal subsystem interruptible condition. One of these interruptible conditions, register Access Complete (HardAcsCmplt), comes from the TEMAC component and is further defined and enabled by the MIS and MIE registers, which are described in Interrupt Status Register and Interrupt Enable Register.

When an interruptible condition occurs, it is captured in this register (represented as the corresponding bit being set to 1) even if the condition goes away. The latched interruptible condition is cleared by writing a 1 to that bit location. Writing a 1 to a bit location that is 0 has no effect. Likewise, writing a 0 to a bit location that is 1 has no effect. Multiple bits can be cleared in a single write.

Important: For any bit set in the Interrupt Status register, a corresponding bit must be set in the Interrupt Enable register for the same bit position to be set in the Interrupt Pending register.

Whenever any bits are set in the Interrupt Pending register, the interrupt signal is driven active-High out of the AXI Ethernet Subsystem. The following figure shows the structure of the interrupt register.

Figure 1. Interrupt Status Register (0x0000_000C) AXI Ethernet Page-1 Sheet.3 Sheet.4 Sheet.5 Sheet.6 Sheet.7 Sheet.8 Sheet.9 Sheet.10 Sheet.11 Sheet.12 Sheet.13 Sheet.85 8 8 Sheet.86 9 9 Sheet.87 31 31 Sheet.88 7 7 Sheet.89 6 6 Sheet.90 Reserved Reserved Sheet.91 HardAcsCmplt HardAcsCmplt Sheet.92 AutoNeg AutoNeg Sheet.93 5 5 Sheet.94 4 4 Sheet.95 2 2 Sheet.96 1 1 Sheet.97 0 0 Sheet.98 3 3 Sheet.99 RxRject RxRject Sheet.100 RxCmplt RxCmplt Sheet.101 RxFifoOvr RxFifoOvr Sheet.102 PhyRstCmplt PhyRstCmplt Sheet.103 RxDcmLock RxDcmLock Sheet.104 TxCmplt TxCmplt Sheet.105 MgtRdy MgtRdy Sheet.106 X14028 X14028 Sheet.107 MSB MSB Sheet.108 LSB LSB Standard Arrow.1 Standard Arrow.59 Sheet.14 Sheet.15 Standard Arrow.16 Standard Arrow.17 Standard Arrow.18 Sheet.19 Sheet.20 Sheet.21

The following figure shows the Interrupt Status register bit definitions.

Table 1. Interrupt Status Register (0x0000_000C)
Bits Name Access Reset Value Description
31:9 Reserved RO 0x0 Reserved: These bits are reserved for future use and always return zero.
8 PhyRstCmplt R/W 0 PHY Reset Complete. When set to 1, this bit indicates the PHY can be accessed. This signal does not transition to 1 for 5 ms after PHY_RST_N transitions to 1.
  • 0 – PHY not ready
  • 1 – PHY ready
7 MgtRdy 1 R/W 0 / 1 Serial Transceiver Ready: This bit indicates if the TEMAC core is out of reset and ready for use. In systems that use a serial transceiver, this bit goes to 1 when the serial transceiver is ready to use. Prior to that time, access of TEMAC core registers does not complete and the subsystem does not operate. In systems that do not use a serial transceiver, this signal goes to 1 immediately after reset.
  • 0 – serial transceiver / TEMAC not ready
  • 1 – serial transceiver / TEMAC ready
6 RxDcmLock R/W 1 Receive DCM Lock: No longer used, but reserved for future use. This bit is always one.
  • 0 – RX digital clock manager (DCM) not locked
  • 1 – RX DCM Locked
5 TxCmplt R/W 0 Transmit Complete: This bit indicates that a frame was successfully transmitted.
  • 0 – no frame transmitted
  • 1 – frame transmitted
4 RxMemOvr R/W 0 Receive Memory Overrun: This bit indicates that the receive Memory overflowed while receiving an Ethernet frame.
  • 0 – normal operation, no overflow occurred
  • 1 – receive Memory overflow occurred and data was lost
3 RxRject 2 R/W 0 Receive Frame Rejected: This bit indicates that a receive frame was rejected.
  • 0 – no receive frame rejected
  • 1 – receive frame was rejected
2 RxCmplt R/W 0 Receive Complete: This bit indicates that a packet was successfully received.
  • 0 – no frame received
  • 1 – frame received
1 AutoNeg R/W 0 Auto-Negotiation Complete: This bit indicates that auto-negotiation of the SGMII or 1000BASE-X interface has completed.
  • 0 – auto-negotiation not complete.
  • 1 – auto-negotiation complete.
0 HardAcsCmplt R/W 0 Hard register Access Complete: This bit indicates that an access of the TEMAC component has completed.
  • 0 – Hard register access is not complete.
  • 1 – Hard register access is complete.
  1. This bit resets to 0 but can change to 1 immediately after reset is removed. This bit can remain at 0 for some time in systems that are using serial transceivers when the serial transceivers are not yet ready for use.
  2. See the following figure for conditions that cause the receive frame reject interrupt to occur. The receive frame reject interrupt occurs for any of the following reasons:
    • The frame does not meet the Ethernet frame requirements (bad FCS, bad length, etc).
    • In addition to the frame being good but not meeting the destination address filtering, the frame also does not match one of the 4 multicast table entries, it is not a broadcast frame, it does not match the unicast address register.
    • The subsystem was built to support extended multicast address filtering (C_MCAST_EXTEND=1).
    • The frame is good and meets the destination address filtering but it is a multicast frame and the multicast reject bit is set in the soft RAF register.
    • The frame is good and meets the destination address filtering but it is a broadcast frame and the broadcast reject bit is set in the soft RAF register.
Figure 2. Subsystem Interrupt Structure