Hello everyone,
Background: I am using McBSP0 on the C6713 to control an SPI DAC. The McBSP configuration is included bellow with the DAC clock being about 4.33MHz. I have noticed that the one write to the SPI does not only cause one write to the DAC. The value is written repeatedly every 9uS or so. I am using the output of the DAC to tune a VCO/PLL combination, which means the slightest change in the signal affects the system.
Question: is it possible to stop the McBSP from writing repeatedly to the DAC?
McBSP Configutation:
MCBSP_Config DAC_Control = {
MCBSP_FMKS(SPCR, FREE, NO) |
MCBSP_FMKS(SPCR, SOFT, NO) |
MCBSP_FMKS(SPCR, FRST, YES) |
MCBSP_FMKS(SPCR, GRST, YES) |
MCBSP_FMKS(SPCR, XINTM, XRDY) |
MCBSP_FMKS(SPCR, XSYNCERR, NO) |
MCBSP_FMKS(SPCR, XRST, YES) |
MCBSP_FMKS(SPCR, DLB, OFF) |
MCBSP_FMKS(SPCR, RJUST, RZF) |
MCBSP_FMKS(SPCR, CLKSTP, NODELAY) |
MCBSP_FMKS(SPCR, DXENA, OFF) |
MCBSP_FMKS(SPCR, RINTM, RRDY) |
MCBSP_FMKS(SPCR, RSYNCERR, NO) |
MCBSP_FMKS(SPCR, RRST, NO),
MCBSP_FMKS(RCR, RPHASE, SINGLE) |
MCBSP_FMKS(RCR, RFRLEN2, DEFAULT) |
MCBSP_FMKS(RCR, RWDLEN2, DEFAULT) |
MCBSP_FMKS(RCR, RCOMPAND, MSB) |
MCBSP_FMKS(RCR, RFIG, NO) |
MCBSP_FMKS(RCR, RDATDLY, 0BIT) |
MCBSP_FMKS(RCR, RFRLEN1, OF(0)) |
MCBSP_FMKS(RCR, RWDLEN1, 16BIT) |
MCBSP_FMKS(RCR, RWDREVRS, DISABLE),
MCBSP_FMKS(XCR, XPHASE, SINGLE) |
MCBSP_FMKS(XCR, XFRLEN2, DEFAULT) |
MCBSP_FMKS(XCR, XWDLEN2, DEFAULT) |
MCBSP_FMKS(XCR, XCOMPAND, MSB) |
MCBSP_FMKS(XCR, XFIG, NO) |
MCBSP_FMKS(XCR, XDATDLY, 0BIT) |
MCBSP_FMKS(XCR, XFRLEN1, OF(0)) |
MCBSP_FMKS(XCR, XWDLEN1, 24BIT) |
MCBSP_FMKS(XCR, XWDREVRS, DISABLE),
MCBSP_FMKS(SRGR, GSYNC, FREE) |
MCBSP_FMKS(SRGR, CLKSP, DEFAULT) |
MCBSP_FMKS(SRGR, CLKSM, INTERNAL) |
MCBSP_FMKS(SRGR, FSGM, FSG) |
MCBSP_FMKS(SRGR, FPER, OF(30)) |
MCBSP_FMKS(SRGR, FWID, OF(12)) |
MCBSP_FMKS(SRGR, CLKGDV, OF(25)),
MCBSP_MCR_DEFAULT,
MCBSP_RCER_DEFAULT,
MCBSP_XCER_DEFAULT,
MCBSP_FMKS(PCR, XIOEN, SP) |
MCBSP_FMKS(PCR, RIOEN, SP) |
MCBSP_FMKS(PCR, FSXM, INTERNAL) |
MCBSP_FMKS(PCR, FSRM, INTERNAL) |
MCBSP_FMKS(PCR, CLKXM, OUTPUT) |
MCBSP_FMKS(PCR, CLKRM, OUTPUT) |
MCBSP_FMKS(PCR, CLKSSTAT, DEFAULT)|
MCBSP_FMKS(PCR, DXSTAT, DEFAULT) |
MCBSP_FMKS(PCR, FSXP, ACTIVELOW) |
MCBSP_FMKS(PCR, FSRP, ACTIVEHIGH) |
MCBSP_FMKS(PCR, CLKXP, RISING) |
MCBSP_FMKS(PCR, CLKRP, RISING)
};
