AURIX™ Write Port via DAS (JTAG)

 One interesting experiment is to write AURIX™ ports via the DAS connection, thus making use of the hidden and low-level JTAG connection to TC275x device.

To understand how to do, we have to study a bit the user manual and the General Purpose I/O Ports and Peripheral I/O Lines (Ports). So, let's have a look at the Infineon-TC27x_D-step-UM-v02_02-EN.pdf User Manual and understand that each port can be configured in different manner (e.g. Pull-down, Pull-up, tri-state):

And since I'm using the TC275 lite kit, we can try to read the LED status or turn-on/off by using the DAS server:

Therefore I will try to set/reset Port P00.6 and P00.5. Such are controllable by P00_IOCTRL4 (port control for pin 4 to 7), so reading 0xF003A014 leads to:

that means a 0xx0010b, thus a input pull-up setting. This info, is now not so much important since the above pins are connected to LEDs, but is good to know for future use.

Let's try now to turn-on and off the LED2 (P00.6)

To do so, we need to halt the execution and then manipulate the bit 6 of P00_OUT:

Since P00_OUT is located at F003A000 (see above manual extraction, where n=0, since is port 0) we just have to write xxxxxx40 or xxxxxx00 to set/reset the pin 6. Since the LED2 is active low, setting the pin 6 will lead to an OFF led, while resetting will lead to an ON led - so the LED will emit light:

By that, I learnt the basics on boundary scan without the need to have a complex and expensive JTAG Boundary Scan tool for AURIX™. Next time we will read the port status via the DAS server...