Need UART VP to start sooner
openmic
Posts: 7
In our application we use a watch dog chip to monitor Javelin activity. We instantiate a UART VP (txUart) and use it to communicate with a PC. The txUart connects to the WDI input of the watch dog chip. So, if the Javelin stops transmitting to the PC (for greater than 2.3 seconds), the watch dog triggers a reset of the Javelin.
Our issue is at start up of the Javelin. Scope traces show that it takes 2.3 or more seconds for txUart to start sending packets after we apply power to the Javelin. This causes the watch dog to trigger. Thus we can never bring up the Javelin into steady state. We could increase the 2.3 second window with capacitor change, but that involves field rework which we want to avoid. We would rather use software to decrease the time it takes for txUart to start sending.
We thought about putting some transmit code into the UART constructor. However, we're unsure if it will work, thinking perhaps the Javelin firmware may prohibit use of a VP until after all instantiation and the code has entered the main(). Is this how it works?
Can you give us some suggestions?
Our issue is at start up of the Javelin. Scope traces show that it takes 2.3 or more seconds for txUart to start sending packets after we apply power to the Javelin. This causes the watch dog to trigger. Thus we can never bring up the Javelin into steady state. We could increase the 2.3 second window with capacitor change, but that involves field rework which we want to avoid. We would rather use software to decrease the time it takes for txUart to start sending.
We thought about putting some transmit code into the UART constructor. However, we're unsure if it will work, thinking perhaps the Javelin firmware may prohibit use of a VP until after all instantiation and the code has entered the main(). Is this how it works?
Can you give us some suggestions?
Comments
See my attached classes.
Both classes go into your application folder.
regards peter