Looking for documents about the OMAP-L138 experimenter board

Hi Helene,

The book is really aimed more at reinforcing DSP concepts using real-time demonstrations than at learning how to program the C6748 at a low level. That’s the reason that the definitions of functions such as, for example, output_sample() and L138_initialise_intr() are ‘hidden’ in file  L138_aic3106_init.c.

I have not written any explicit explanations of these functions beyond what is in the book, e.g. pages 42-52 and 236-248.

The function definitions in file L138_aic3106_init.c are not very comprehensively commented, I admit. They were written based on reading the relevant sections of the TI datasheets for the AIC3106 codec and for McASP and EDMA3 and follow initialisation sequences described therein. In the aforementioned pages of the book I tried to explain the important actions of the functions concerning, for example, events, interrupts, and setting up INTMUX and ISTP. I tried also in the book to explain some of the control registers in the AIC3106 codec. At the lowest level, calls are made to some functions, e.g. AIC3106_writeRegister() and EVMOMAPL138_lpscTransition() supplied by logicPD in the board support library (BSL).

Essentially, L138_aic3106_init.c contains function definitions for

i)                    Input and output using the AIC3106.

ii)                   The often-used pseudorandom noise generator.

iii)                 Initialisation of the board.

There are three different initialisation functions, depending on whether polling, interrupt or DMA-based i/o (via the AIC3106) is used. The three functions L138_initialise_poll(),L138_initialise_intr(), and L138_initialise_edma() are not very different and each calls L138_init_aic3106_registers() and then one of  L138_init_mcasp_poll(),L138_init_mcasp_intr(), or L138_init_mcasp_edma(). The three last-named functions differ only very slightly from each other concerning if and how interrupts are generated by McASP.

L138_init_aic3106_registers() is based very closely on information in the AIC3106 datasheet. L138_init_mcasp_poll(),L138_init_mcasp_intr(), and L138_init_mcasp_edma() are based very closely on the initialisation procedures described in the McASP user guide.

If you are interested more in low–level programming of the C6748, I recommend looking at the latest version of the C6000 teaching ROM written by Jacob Fainguelernt. http://e2e.ti.com/group/universityprogram/educators/w/wiki/2041.c6000-teaching-rom.aspx

Hope this helps.

 Regards,

 Donald