5.5.3. Interrupt Bottom Half ISR Handler - The bottom half ISR handler mainly controls a chain of events to the SPI controller device or clock chips, and the F-Tile JESD204C IP.

The bottom half ISR handler mainly controls a chain of events to the SPI controller device or clock chips, and the F-Tile JESD204C IP.

The following tables describe the ISR handler recommendations for different TX and RX error types.

Table 16. TX Interrupt Handler Recommendations
Error Type	ISR Handler Operation
`tx_sysref_lemc_err`	This error occurs when the `SYSREF` signal continuously resets the LEMC counter at an unexpected time, which violates the LEMC period. The processor needs to check the setting for all LEMC counters configured on the F-Tile JESD204C IP converter device and clock chip.
`tx_dll_data_invalid_err`	This error occurs when data bubble appears on the Avalon^® streaming interface in the F-Tile JESD204C TX base core. The processor needs to probe the upstream device the find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`tx_frame_data_invalid_err`	This error occurs when data bubble appears on the Avalon^® streaming interface in the F-Tile JESD204C TX transport layer. The processor needs to probe the upstream device the find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`cmd_invalid_err`	This error occurs when data bubble appears on the Avalon^® streaming command interface in the F-Tile JESD204C TX link layer. The processor needs to probe the upstream device the find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`tx_gb_underflow_err`	This error is flagged when at least 1 instance of the TX gearbox FIFO is having underflow. The processor ensures that the system design provides the correct `j204c_txlink_clk` frequency of (data rate)/66 to the IP.
`tx_gb_overflow_err`	This error is flagged when at least 1 instance of the TX gearbox FIFO is having overflow. The processor ensures that the system design provides the correct `j204c_txlink_clk` frequency of (data rate)/66 to the IP.
`efifo_overflow_err`	This error is flagged when an overflow happens in any of the lane's TX eFIFOs. The processor ensures that the system design provides system PLL clock `sysclk` is equal or higher than native clock frequency.
`src_tx_alarm`	This error is flagged when the F-tile's soft reset controller generates a TX alarm. The processor ensures the `refclk` supply to transceiver is accurate.
`syspll_lock_err`	This error is flagged when the system PLL loses lock while the F-Tile JESD204C link is up and running. The processor ensures that the `refclk` to external system PLL is accurate.
`tx_pll_lock_err`	This error is flagged when one or more lanes of the transceiver TX PLL looses lock while the F-Tile JESD204C link is up and running. The processor ensures that `refclk` supply to transceiver is accurate.

Table 17. RX Interrupt Handler Recommendations
Error Type	ISR Handler Operation
`rx_sysref_lemc_err`	This error occurs when the `SYSREF` signal continuously resets the LEMC counter at an unexpected time, which violates the LEMC period. The processor needs to check the setting for all LEMC counters configured on the F-Tile JESD204C IP converter device and clock chip. By default, the link automatically reinitializes when this signal is asserted.
`rx_dll_data_ready_err`	This error occurs when the Avalon^® streaming interface in the F-Tile JESD204C RX base core does not have backpressure and yet, the upstream device indicates that it is unable to take in data. The processor needs to probe the upstream device to find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`rx_frame_data_ready_err`	This error occurs when the Avalon^® streaming interface in the RX transport layer does not have backpressure and yet, the upstream device indicates that it is unable to take in data. The processor needs to probe the upstream device to find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`rx_cmd_ready_err`	This error occurs when the Avalon^® streaming command interface in the RX link layer does not have backpressure and yet, the upstream device indicates that it is unable to take in data. The processor needs to probe the upstream device to find out why it has stalled and take further action. Note: By design, you should calculate the data throughput to ensure that there are no data bubbles in the design. This additional protection is to minimize errors in the system.
`rx_cdr_locked_err`	This error occurs because of incoming data stream that causes RX PMA to unlock its CDR. The processor may not be able to recover from such error. PMA debug is required.
`rx_lane_deskew_err`	This is a system error. You need to investigate total skew and the E parameter settings.
`rx_invalid_sync_header`	This error occurs when the IP receives “00” or “11” in the expected SH location. Refer to the JESD204C Specifications for action required for hardware.
`rx_invalid_eomb`	This errors occurs when “00001” sequence in the pilot signal is not received at an expected location in the sync word. Refer to the JESD204C Specifications for action required for hardware.
`rx_invalid_eoemb`	This error occurs when the EoEMB identifier in the pilot signal has an unexpected value. Refer to the JESD204C Specifications for action required for hardware.
`rx_cmd_par_err`	The error is flagged when the final parity bit in the command channel data for a given Sync Word does not match the calculated parity for the received command channel bits. Refer to the JESD204C Specifications for action required for hardware.
`rx_crc_err`	This error occurs when the receive CRC generator has calculated a parity which does not match the parity received in the Sync Word. The hardware tries to reinitialize but if the error persists, the processor is required to find out the cause of CRC error.
`rx_gb_underflow_err`	This error is flagged when at least 1 instance of the RX gearbox FIFO is having underflow. This underflow error occurs when the frequency ratio between `j204c_rxlink_clk` and `j204_rxphy_clk` is larger than 32:33. In this scenario, the `j204c_rxlink_clk` clock is unexpectedly faster than the `j204c_rxphy_clk` clock. When this error occurs, the system needs to reset. To prevent this error from occurring, the frequency ratio of `j204c_rxlink_clk` and `j204_rxphy_clk` must be 32:33.
`rx_gb_overflow_err`	This error is flagged when at least 1 instance of the RX gearbox is having overflow. This overflow error occurs when the frequency ratio between `j204c_rxlink_clk` and `j204_rxphy_clk` is smaller than 32:33. In this scenario, the `j204c_rxlink_clk` clock is unexpectedly slower than the `j204c_rxphy_clk` clock. When this error occurs, the system needs to reset. To prevent this error from occurring, the frequency ratio of `j204c_rxlink_clk` and `j204_rxphy_clk` must be 32:33.
`rx_sh_unlock_err`	This error indicates that SH alignment is lost. The hardware always tries to reinitialize for this error.
`rx_emb_unlock_err`	This error indicates that EMB alignment is lost. The hardware always tries to reinitialize for this error.
`rx_eb_full_err`	This error could be caused by the same reason that causes deskew error. You need to investigate total skew and the E parameter settings.
`rx_ecc_corrected_err`	This error keeps track of the EC detected. Intel recommends you to enable this error so that the processor can keep track of the EC detected. The processor can enter error detection and correction routine.
`rx_ecc_fatal_err`	ECC fatal error that indicates bad data has been sent to the upstream device. The severity of this error depends on the system. For example, ultrasound applications may still cope with uncorrectable ECC errors. However, systems where data packets should never be lost, the system may reset the core.
`src_rx_alarm`	This error is flagged when the F-tile's soft reset controller generates a RX alarm. The processor ensures the `refclk` supply to transceiver is accurate.
`syspll_lock_err`	This error is flagged when the system PLL loses lock while the F-Tile JESD204C link is up and running. The processor ensures that the `refclk` to external system PLL is accurate.

5.5.3. Interrupt Bottom Half ISR Handler - The bottom half ISR handler mainly controls a chain of events to the SPI controller device or clock chips, and the F-Tile JESD204C IP. - 2025-12-16

F-Tile JESD204C IP User Guide