Bios: biospsp_01_30_01
Hardware: OMAPL138 Evm “Experimenter” board
CCS: 4.2.5
I have taken the bios example code for initialization of McASP as a master (transmit) and slowly tweaked the channel parameters towards what I will need on our own custom hardware.
I am testing the bios calls on the evm to verify that I am using them properly.
The sample code assumes 1 serializer, 32 bit words, TDM mode, 1 slot, buffer format Mcasp_BufferFormat_1SER_1SLOT
Ours will be 1 serializer, 16 bit data, TDM, 6 slots.
When I change number of data bits from 32 to 16, the SIO_create() of the tx stream for the McASP properly returns a handle.
When I change the 1 slot to 6 slots, it properly returns a handle (though the fact that I have change it to 6 slots but the buffer format is still “1SER_1SLOT” makes me wonder why it does not complain).
When I change the buffer format to Mcasp_BufferFormat_1SER_MULTISLOT_INTERLEAVED or Mcasp_BufferFormat_1SER_MULTISLOT_NON_INTERLEAVED, SIO_create() returns a NULL indicating it could not create the stream.
[My heap is 1Mbyte BTW - plenty big enough.]
My question: why? Is there some other change to the channel parameters I need to make for the SIO_create() to work properly? There must be some simple other tweak I need to do that I’m missing because I’m new to the TI BIOS stuff.
Here is the configuration of my channel parameters for the failure mode:
Mcasp_HwSetupData mcaspXmtSetup =
{
/* .xmask = */ 0x0000FFFF, /* 16 Data bits are used */
/* .xfmt = */ 0x000080F0, /* 1 bit dly,MSB first,16 bit,Rotate */
/* .afsxctl = */ 0x00000002, /* internally generated fsync */
/* .xtdm = */ 0x0000003F, /* 6 slots active */
/* .xintctl = */ 0x00000003, /* underrun and sync error active */
/* .xstat = */ 0x000001FF, /* reset any existing status bits */
/* .xevtctl = */ 0x00000000, /* DMA mode */
{
/* .aclkxctl = */ 0x00000020, /* div = 1, clk = internal */
/* .ahclkxctl = */ 0x00008004, /* div by 16 */
/* .xclkchk = */ 0x00000000
}
};
Mcasp_ChanParams mcasp_tx_chanparam_sample =
{
0x0001, /* number of serializers */
{Mcasp_SerializerNum_15,}, /* Uint32 indexOfSersRequested[16u]; */
(Mcasp_HwSetupData *)&mcaspXmtSetup, /* pointer to output buffer */
FALSE, /* DMA flag */
Mcasp_OpMode_TDM, /* TDM mode */
Mcasp_WordLength_16, /* word width */
NULL, /* Ptr userLoopJobBuffer; */
0, /* Uint16 userLoopJobLength; */
NULL, /* Ptr edmaHandle; */
NULL, /* Mcasp_GblCallback gblCbk; */
1, /* Uint32 noOfChannels; */
Mcasp_BufferFormat_1SER_MULTISLOT_INTERLEAVED, /* Mcasp_BufferFormat dataFormat; */
TRUE, /* Bool enableHwFifo; */
TRUE /* Bool isDataPacked; */
};
