This version (15 Nov 2023 11:41) was approved by Michael Hennerich.The Previously approved version (25 Jul 2022 11:53) is available.
Table of Contents
JESD204B Status Utility
The jesd_status utility is in some sense similar to the JESD204B Eye Scan application. It currently doesn't support EYE SCAN, but can show all the link and lane status information, similar to the JESD204B Eye Scan, while being much more lightweight and doesn't require a graphical desktop environment. It can be started from a serial root console or from a SSH terminal.
It interfaces with the JESD204 Interface Framework:
And reads the status information of all devices from SYSFS, aggregates and processes them and finally pretty prints it to the terminal in a continuous fashion. A single key event will terminate the application.
In case this utility is not available on your platform you may run following command below to extract similar information:
root@analog:/# grep "" /sys/bus/platform/drivers/axi-jesd204*/*/status /sys/bus/platform/drivers/axi-jesd204*/*/lane* /sys/bus/platform/drivers/axi-jesd204*/*/encoder
| What | Comment |
|---|---|
| Link is [enabled|disabled] | Link state indicator. In case link state is disabled, that either means the link was never enabled or that an error occurred and the FSM rolled back and disabled the link. In the jesd204-fsm case this can be prevented by using the jesd204-ignore-errors; devicetree property when placed in the jesd204-fsm jesd204-top-device node. |
| Link status | Depending on the encoding JESD204B/C 8B10B/64B66B there can be different values RESET, WAIT, CGS, ILAS, etc., DATA Please see link layer documentation for the state machine: JESD204B/C Link Receive Peripheral \ JESD204B/C Link Transmit Peripheral In general DATA is the desired state indicating proper operation. |
| SYNC is [asserted|deasserted] (8B10B only) | State of the external SYNC signal. |
| SYSREF captured: [Yes|No] (Subclass 1 only) | Yes indicates that a SYSREF pulse was captured. |
| SYSREF alignment error: [Yes|No] (Subclass 1 only) | Yes indicates that a SYSREF event has been observed which was unaligned, in regards to the LMFC/LEMC period, to a previously recorded SYSREF event. |
| Lane rate | The SERDES lane rate / bit clock. |
| [LMFC|LEMC] rate | Frequency of the internal local multiframe clocks (LMFC)/ local-multiblock-clock (LEMC). |
| Lane rate / [40|66] | Is equal to the desired Link Clock frequency. |
| Reported Link Clock | Is the Link Clock frequency which is reported by the common clock framework. If this rate is different from the desired Link Clock frequency, there is likely a problem. For example the clock provider wasn’t able to set the desired value. |
| Measured Link Clock | Is the measured Link Clock, using a frequency counter inside the Link Layer Peripheral. For proper operation desired, reported and measured frequency must match. |
| Desired Device Clock | In case this value is different from the Desired Link Clock, this indicates Dual Clock Operation required by the Gearbox. Please see Gearbox/Dual Clock Operation in the Link Layer Peripheral documentation: JESD204B/C Link Receive Peripheral \ JESD204B/C Link Transmit Peripheral The Device Clock is typically generated by the clock provider which also provides SYSREF. |
| Reported Device Clock | Is the Device Clock frequency which is reported by the common clock framework. If this rate is different from the desired Device Clock frequency, there is likely a problem. For example the clock provider wasn’t able to set the desired value. |
| Measured Device Clock | Is the measured Device Clock, using a frequency counter inside the Link Layer Peripheral. For proper operation desired, reported and measured frequency must match. |
Source
Related device drivers
Running the software
The software is started from the command line (it's better to do this as root):
Usage: jesd_status [-s] [-p PATH]
-s Simple mode no boxes and frames (useful for serial terminals)
-p Allows setting a different directory root. Default is /.
This is useful when running the tool remote
Running local
This specifies any root shell prompt running on the target
root@analog:~# jesd_status
Running local via a simple terminal
Depending on the terminal used colors might be unsupported and boxes, frames might not be properly displayed. The -s option allows to disable boxes, while setting the TERM variable will fix the display.
This specifies any root shell prompt running on the target
root@analog:~# TERM=vt100 jesd_status -s
resources/tools-software/linux-software/jesd_status.txt · Last modified: 15 Nov 2023 11:41 by Michael Hennerich