Manual Delay Setting
We will now try manually setting delays for the trace data signals based on the RTM log.
Look at the last set of RTM_DELAY_X entries displayed in the log.txt file (where X is a number from 1-32).
Note: You will set the DSTREAM-PT DELAY_TRACE_SIGNAL configuration items in the platform configuration's .sdf, .rcf, or .rvc file based on the values shown for RTM_DELAY_X. What value you use is based on the RTM_DELAY_X values in the log.
- If the all the RTM_DELAY_X entries have a least significant byte of 0x00 or 0x1f, you will set use a trace data signal delay value of 0x10.
- If a few of the RTM_DELAY_X entries have a least significant byte of 0x00 or 0x1f, but some of the least significant byte values are between 0x00 and 0x1f, you will use a trace data signal delay of one of the non-0x00 or non-0x1f values.
The DELAY_TRACE_SIGNAL values are based in picoseconds at a 82 picosecond resolution, so you will need to convert the least significant byte value shown in RTM_DELAY_X using the below formula:
DELAY_TRACE_SIGNAL_X = converted to decimal(RTM_DELAY_X bits[7:0]) * 82
For example, a least significant byte of 0x10 equals a trace data signal delay of 1312.
- Save a copy of the .sdf, .rcf, or .rvc file before any modifications are made.
- Open the platform configuration .sdf, .rcf, or .rvc as a text file.
- Set a bit for every bit of the target's trace port size to RTM_INITIAL_DELAY_OVERRIDE_ENABLES configuration item. For example, if you have a 16 bit trace port, then you would set <RTM_INITIAL_DELAY_OVERRIDE_ENABLES Type = "Int32">0xFFFF</RTM_INITIAL_DELAY_OVERRIDE_ENABLES>. This will override all the delay times used for all the trace data signals.
Set the DELAY_TRACE_SIGNAL_X configuration items to the trace data delay value determined in step 1. For example, if you want to set a trace data delay value of 1312 ps to every trace data signal in a 16-bit trace port, you set <DELAY_TRACE_SIGNAL_X Type = "Int32">1312</DELAY_TRACE_SIGNAL_X> where X is 1-16.
Note: You only need to set trace data signal delays for the size of your trace port. For example, if you have a 4-bit trace port, you set delays for DELAY_TRACE_SIGNAL_1 - 4 and leave the rest unaltered.
- Click File → Save.
- Start a new dbghw_log_client session using a new log file as output (like <writable path>\log3.txt).
- If you are editing the .sdf, .rcf, or .rvc outside Arm Development Studio, rebuild the configuration database in Arm Development Studio by clicking Window → Preferences → Arm DS → Configuration Database → Rebuild database.
- If you are currently connected to the target with Arm Development Studio, disconnect and then re-connect to the target.
- Perform the trace capture again.
Note: You may need to run the capture for several seconds to ensure good output.