U16 timerVal = (U16)-1027; erm...if i'm using this code, how to define that U16? I'm not that good in using this U16...not familiar enough....Need to define it on top of the code? can use unsigned int U16 timerVal;?
It is probably just type definition shorthand for a 16-bit unsigned integer. You will often find this type of definition in a portability header file, which might contain something like:
typedef signed char S8; typedef unsigned char U8; typedef signed short S16; typedef unsigned short U16; typedef signed long S32; typedef unsigned long U32;