Here are some possible interpretations depending on the context:
* Cracked me up: This means something made you laugh uncontrollably.
* Cracked me open: This could be a figurative expression meaning something made you vulnerable or emotional. It's not a common idiom but could be used in a specific context.
* Cracked the code: This means you figured something out, like a puzzle or a secret.
To understand the meaning, you need more context. Can you provide an example of how you heard "cracked me" used?