Non-intrusive register profiling in ARM920T

Hello,

I am currently using a ARM920T core based S3C2440 processor. I want to read the registers out of ARM9 in real-time. There is no OS running, just a super loop. Currently, I am using an interrupt driven approach, where timer 2 overflows and goes to ISR. In the ISR I send the required register data to the Host PC through the UART. I believe this method of profiling is too intrusive(carries a lot of overhead).

I know there are tools relating to core sight technology, but I cannot update the entire development board and JTAG tools just to do that. They are very costly.

The board can also be run using linux. it runs busybox, and I tried using "devemem" applet but that is also a very intrusive method (having high overhead).

Can anyone suggest me any other method to read hardware physical registers using OS or no OS in the most efficient way and in real-time.

Thanks,
Patrick