readmetpuapp.txt

来自「mpc564 时钟中断 时钟中断」· 文本 代码 · 共 109 行

To All, (et al),

	Below is an email that I sent out to give a basic description of the
file structures that we are using for the code examples of the TPU functions.
This is meant to provide a high level road map and description of the
supporting code. Application Program Interface.


***********************************************************************************

I call the levels of code "Groups" here. Customers will only write for Group four.
We will write the code for group three (and an example/test file at the group four
level). Below is a description for all layers of the groups.

The file structure is as follows:

Group One: The basic header files: 
    These are the basic files that define all of the registers. That way, we can 
point to a bit or a whole register with a TPU.TPUMCR.R = 0x0000 kind of call. There 
is a more global call that does the same thing: tpu -->TPUMCR.R = 0x0000. This does 
the same thing when "tpu" is properly defined (see tpu_fqd_example1).

When you include mpc555.h  ---All of the header files will enter the program compile.
                 mpc565.h

Group Two: The TPU utility header files.
    These files were generated by Jeff to provide basic TPU function calls.
    File: mpc500_util.h ---> defines the values for the TPU.
    File: mpc500_util.c ---> Contains the functions for the TPU. Note that the basic 
                              function will have three inputs. 1) which TPU (A, B, 
                              or C); 2) which  channel is being accessed; 3) a 
                              parameter value. There may be different combinations 
                              (more or less) of these inputs.
    File: mpc500.c --> Sets up the hardware and clock speed (as an input). This would 
                        take the place of Diab Data's Crt0.s by performing the 
                        following funcitons:
                        1) Disable watchdog timer; 2) Place the machine in expanded mode;
                        3) Normal slew rate on pads; 4) Optional: set up chip selects; 
                        5) Set PLL clock speed; 6) Enable timebase and decrementor;
                        7) Set the IMB to full speed; etc.
    File: mpc500.dld --> Link file for compiling the software.
    File: makefile --> Used to compile the software with the command: "make -f makefile"
                        This command is given in a command line window which has access
                        (paths) to all of the required source files.


Group Three: The function API's.
    The example given by Jeff is for the FQD function. These are the files that 
    "we" are writing for the customer to use. These files are the bridge between 
    the header files and the customers top level "*.c" code. The customer will 
    make many one line function calls into these files. There are two files here:
      1) tpu_fqd.c ---> contains the functions (which we are calling the API) for 
                         the the fqd function. The functions in your file should 
                         perform the following tasks:

             1) Initialization --->There will always be an initialization for the 
                  particular function that is being called. The name in this 
                  example is tpu_fqd_init( ). Just replace your function letters 
                  with the fqd. This function will set up all of the control registers 
                  in the TPU for your function. Follow Jeffs' example where the TPU 
                  channel is disabled, given a function, initialized, and finally, 
                  re-enabled. (By the way, for my TSM function, I had 12 inputs,
                  one input included a three by eight table.) Your function may 
                  have less inputs than mine.

             2) Setting values ---> If any of the parameters need to be specifically 
                  changed, write a function that addresses that channel address 
                  location and sets the value. NOTE: many values may be changed 
                  but might not be the right thing to do. For example: I could 
                  have had (and did) a function that changed the Pin_Sequence for 
                  the TSM. This could be done, but, probably would destroy a real 
                  motor if used while the motor was running! The best way to change 
                  values is to call another initialization call (see #1 above) if 
                  there is a "dangerous" variable to be changed.

             3) Reading values ---> These calls are to read any current or set 
                  status for the function. The customer would probably definately 
                  want calls in this category if current values are important to 
                  the program flow. These values can be polled for a match and 
                  change program flow depending on a specific value. My TSM 
                  function is also set to make an interrupt which is what I am 
                  using to determine when I have a match between desired and 
                  current position.

     2) tpu_fqd.h ---> defines the constant values for the fqd. Also, the 
            prototypes for each function in tpu_fqd.c resides here. Note: the 
            prototype is identical to the function call header.

Group Four: The example file.c. This is the customers application that they 
            will write. We will need to also write an example file to run the 
            code for our function. This provides an example for the customer
            as well as a test vehicle. The "main()" function is located here.
            The file in our example here is called: tpu_fqd_example1.c, 
            tpu_fqd_example2.c, and tpu_fqd_example3.c. These will also have local 
            functions that the customer will need to generate for their own 
            application. My TSM interrupt function is placed in my tpu_tsm_ex1.c 
            file at this level.

            I started with Jeff's example file by just substituting all of the 
            "fqd's" with "tsm's". My example file is called: tpu_tsm_ex1.c.