I have been working on getting Example 7.1.5 from this document: http://cache.freescale.com/files/32bit/doc/quick_ref_guide/KQRUG.pdf working on our MK02.
I have the PIT configured and working, but whenever I try to reference the DMA MUX registers for either read or write operations, I get a hard fault. The register I'm trying to access is DMAMUX_CHCFG0 at address 0x40021000.
Reading section 21.3 of this manual: http://cache.freescale.com/files/microcontrollers/doc/ref_manual/K02P64M100SFARM.pdf says that the address is at the location I'm trying to access. I'm a little confused why even trying to access the location causes a hard fault. In any case, I'm wondering if you could ask around and find out if anyone has this sample running on the MK02. I want to do exactly what the sample does which is read the ADC at a particular frequency and DMA the results to a block of memory.
The code I'm using is literally as simple as:
uint8_t test = DMAMUX_CHCFG0;
LOG_DEBUG1("DMAMUX_CHCFG0: %x\n", test);
I've also looked at the definitions from the mac7100.h file used by Keil. That defines the config register as DMAMUX_CHCONFIG0 at address 0xFC084000. This doesn't match the hardware docs I have so I assume it is referencing a different chip. Just for fun I tried accessing the register but got the same result.
Anyway, thanks in advance for any clues you can provide.
已解决! 转到解答。
Hello,
Is the clock gating for the DMAMUX enabled? Please be sure that the field DMAMUX in the register SIM_SCGC6 is enabled before to write/read in the DMAMUX_CHCFGn register.
Best regards,
Earl.
Hello,
Is the clock gating for the DMAMUX enabled? Please be sure that the field DMAMUX in the register SIM_SCGC6 is enabled before to write/read in the DMAMUX_CHCFGn register.
Best regards,
Earl.