MKL25Z128VLK4 number of DMA channels -?

[aaronm]

Hi, both documents KL25P80M48SF0RM and KL25P80M48SF0 indicate that the KL25Z has four (4) DMA channels, but the MKL25Z4.h header file has only one:

/* DMA - Peripheral instance base addresses */
/** Peripheral DMA base address */
#define DMA_BASE                                 (0x40008000u)
/** Peripheral DMA base pointer */
#define DMA0                                     ((DMA_Type *)DMA_BASE)
/** Array initializer of DMA peripheral base addresses */
#define DMA_BASE_ADDRS                           { DMA_BASE }
/** Array initializer of DMA peripheral base pointers */
#define DMA_BASE_PTRS                            { DMA0 }
/** Interrupt vectors for the DMA peripheral type */
#define DMA_CHN_IRQS                             { { DMA0_IRQn, DMA1_IRQn, DMA2_IRQn, DMA3_IRQn } }

Obviously, the code overrides anything in the documentation, but is the documentation wrong, or was the "four DMA" channels for a different model of the MK25Z?

[aaronm · Accepted solution]

On further reading, I see where I misunderstood: There's one DMA peripheral, but that peripheral has four channels.

/** DMA - Register Layout Typedef */
typedef struct {
       uint8_t RESERVED_0[256];
  struct {                                         /* offset: 0x100, array step: 0x10 */
    __IO uint32_t SAR;                               /**< Source Address Register, array offset: 0x100, array step: 0x10 */
    __IO uint32_t DAR;                               /**< Destination Address Register, array offset: 0x104, array step: 0x10 */
    union {                                          /* offset: 0x108, array step: 0x10 */
      __IO uint32_t DSR_BCR;                           /**< DMA Status Register / Byte Count Register, array offset: 0x108, array step: 0x10 */
      struct {                                         /* offset: 0x108, array step: 0x10 */
             uint8_t RESERVED_0[3];
        __IO uint8_t DSR;                                /**< DMA_DSR0 register...DMA_DSR3 register., array offset: 0x10B, array step: 0x10 */
      } DMA_DSR_ACCESS8BIT;
    };
    __IO uint32_t DCR;                               /**< DMA Control Register, array offset: 0x10C, array step: 0x10 */
  } DMA[4];
} DMA_Type;

See the "DMA[4]" near the bottom.  I'm glad we cleared that up.