Hello, I try to read USB spec but I have no answer. Perhaps you could help me Configuration: host (full speed) using interrupt mode + hub1 + device1 +hub2
+device2 devices are also full speed.The host must do on each cycle:
1) read inputs(4 bytes) on device1 2) read inputs(4 bytes) on device2 3) write outputs(4 bytes) on device1 4) read inputs(4 bytes) on device2I would like to know if a :
- Q1) Realtime is possible on the 2 devices ?
- Q2) What will be the host cycle time?
- Q3) Cycle time if host is High speed and devices are Full speed?
- Q4) Cycle time if host is High speed and devices are also High speed?
Here are my answer but I am sure I am wrong. Please correct me. Q1: Yes is can be realtime with a very small jitter Q2: 1) 1ms + 1 ms (hub) + 1ms 2) 1ms + 1 ms + 1ms 3) 1ms + 1 ms + 1 ms 4) 1ms + 1 ms + 1 ms Total = 12ms Q3: No improvment because devices are Full speed = 12 ms Q4: 12 microframes = 1.300 ms