MIPI CSI-2 RX Subsystem v4.0
84
PG232 July 02, 2019
Appendix B:
Debugging
- Verify MIPI CSI-2 RX Controller interrupt status register to see if any ECC errors
getting reported. If there is frequent ECC 2-bit error getting reported means
some of the packets are not getting processed by MIPI CSI-2 RX Controller.
• Packets received by MIPI CSI-2 Subsystem with PPI Level Errors (like SoT Error, SoT sync
Error) and/or Controller level errors (like ECC 1-bit, ECC 2-bit, CRC).
°
Possible causes:
- Lane position mismatch between source (sensor) and MIPI CSI-2 RX Subsystem.
- Noise detected by MIPI DPHY as a valid packet
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Debug instructions:
- Verify Lane positions of source (sensor) and MIPI CSI-2 RX Subsystem are
matching. Lane0 holds first byte of the packet, Lane1 holds the next byte and so
on.
- When HS_SETTLE parameter of MIPI DPHY is not sufficient enough during LP to
HS transition, MIPI DPHY may detect noise as a valid packet and when
subsequently processed by MIPI CSI-2 RX Controller reports these packets are
erroneous packets. Increase HS_SETTLE value either through MIPI DPHY registers
or through C_HS_SETTLE_NS parameter(hidden) available in MIPI CSI-2 RX
Subsystem.
For more debug information on MIPI DPHY, refer the
MIPI D-PHY LogiCORE IP Product Guide
(
PG202
. To debug further, capture the PPI signals using the Vivado® Logic analyzer
and confirm the bytes received through source (sensor) are as expected for short and long
packets.
Interface Debug
AXI4-Lite Interfaces
Read from a register that does not have all 0s as a default to verify that the interface is
functional. See
for a read timing diagram. Output
s_axi_arready
asserts when
the read address is valid, and output
s_axi_rvalid
asserts when the read data/response
is valid. If the interface is unresponsive, ensure that the following conditions are met:
• The
lite_aclk
inputs are connected and toggling.
• The interface is not being held in reset, and
lite_aresetn
is an active-Low reset.
• The main subsystem clocks are toggling and that the enables are also asserted.
• If the simulation has been run, verify in simulation and/or a debug feature capture that
the waveform is correct for accessing the AXI4-Lite interface.