Arturo Garcia

MC9S08GT60 TPM Configuration Register value changes

Discussion created by Arturo Garcia on May 30, 2016

In one application we are using an MC9S08GT60 MCU for displaying text in an LCD. This LCD requires us to implement some delays between commands. These delays consist in a function call that has a cycle that verifies the value of a timer and refreshes the Watchdog. We are using one of the TPM modules in the MCU as timer. In some cases it happens that the application gets cycled forever. I tracked down this situation and discoverd the application is in this cycle and the timer is not running. Verifying the memory addresses, I discovered the TPM Status and Control register has a value that does not correspond to a valid value for the application. Its normal value is 0x4F, with the timer overflow flag active it is 0xCF and when cycled, it has ALWAYS a value of 0x01. No other register next to it has a different value from the configured and correct ones. We wonder if some process of the MCU causes this situation and how could we deal with it.


Thanks in advance.