Hands-On RTOS with Microcontrollers

Performance analysis

Now, let's take a look at the performance of this driver implementation. There are several aspects to consider. Unless a transfer is complete, the ISR will normally only transfer a byte into rxBuff. In this case, the interrupt is fairly short, taking less than 3 us to complete:

After all 16 bytes have been received, the ISR execution gets a bit more interesting and looks a bit more similar to the previous example:

Here are some noteworthy points from the preceding screenshot:

1. After all the bytes have been placed into ...