HC12: Connecting to Hardware

In the part of the tutorial, we will show how to connect and configure the Elektronikladen ComPOD/NG BDM pod for use with an MC9S12DP256 target. Our target board is the Axiom Adapt9S12.

If you are using a different BDM pod, a different HC12 variant - or even NoICE for another processor family, you will still find useful information here. Then try NoICE help on setting up and using

• other BDM pods for HC12
• AN2548 monitor for HC12
• other BDM pods for HCS08
• AN2140 monitor for HCS08
• MON08 monitor for HC08
• jtag for MSP430
• the NoICE serial monitor

If you haven't done so already, we recommend that you go through Running NoICE for the first time before reading this part of the tutorial.

Installing and Connecting the BDM Pod

1. Turn off power to the target.

2. Tie the MODA and MODB pins of your target to ground (Single Chip mode). If your board is a commercial development board, there are likely to be jumpers or DIP switches for MODA and MODB. Consult your board's documentation. If you are using these pins as port pins, you may need extra circuitry to hold the pins low during reset.

   In conjunction with the BDM pod, MODA=MODB=0 allows NoICE to start the chip in Special Single Chip mode. If you start in any other mode, the processor will begin executing instructions immediately, and NoICE may not be able to control it.

3. Connect the pod to the BDM connector on your target. Be sure to orient the connector correctly, or damage to the pod or the target board may result.

   Pin 1 on the BDM cable is almost always indicated by a red stripe on the edge of the cable.

   Pin 1 of the BDM connector on the target board is often indicated by a "1" on the silk-screen. If not, look on the back of the board. Pin 1 is usually indicated by a square pad as shown in the diagram.

4. Connect the serial cable from the ComPOD to your PC.

5. Turn on power to the target.

6. Run NoICE.

7. Select "Target Communications" from the "Options" menu.

8. From the "Interface" drop list, select "Elektronikladen ComPOD / NG"

   Select the appropriate serial port. The baud rate of the ComPOD is fixed. Set Bus Frequency to match the target. Our board has an 8 MHz crystal, so the bus frequency is 4 MHz. (Even if you plan to enable the PLL later, set Bus Frequency to the initial frequency out of reset.) Select our Target Chip: MC9S12Dx256 Flash (this includes the DG, DJ, DP, and DT256) The DP256 can use memory paging (PPAGE) to get beyond 64K. We won't use that feature in this example. We want to debug in Flash, so check "Use Hardware Breakpoints" and "Use Flash/EEPROM Burner"

9. Press "OK".

Press "OK" in the Target Communications dialog, and NoICE will show an initial display like that shown below. If you exit NoICE and come back in, you will return right here. In this case, memory contains a previously-burned program. Since the reset vector contains 4000, that is where PC starts out. NoICE disassembles from the PC. At this point, you may wish to repeat the simulator examples on real hardware.

The next step is to burn a program into Flash. This example uses ImageCraft ICC12, as described in the previous section of the tutorial, Compiling for Source-level Debugging.

You can follow along even if you don't have this compiler. All files necessary for you to run the NoICE demo may be downloaded here: hellofoo.zip. Setup for other compilers is generally similar.

Run NoICE. Select "File", "Load...". By default, you will see hex files such as hellofoo.s19. You could load that, but all you would get would be disassembly, as the s19 file doesn't contain any symbolic debug information. So change the "Files of type" to"ImageCraft DBG files". Be sure that the check-box labeled "S2 records have linear addresses" is checked. This must be checked if the "linear" setting was used in ICC12. If must be unchecked if the "CPU/Banked" setting was used in ICC12. Navigate to hellofoo.dbg and press "OK". NoICE help on LOAD More on "linear" versus "banked"

When you Load the file into the Flash range, a progress dialog appears: It shows the address being burned and the progress of the burn.

Once burning is completed, you can continue with the source-level debugging example

NoICE help

NoICE help on all supported BDM pods