Visible to Intel only — GUID: iga1446069990627
Ixiasoft
Visible to Intel only — GUID: iga1446069990627
Ixiasoft
31.8.14. alt_msgdma_construct_extended_descriptor
Prototype: | static int alt_msgdma_construct_descriptor (alt_msgdma_dev *dev, alt_msgdma_extended_descriptor *descriptor, alt_u32 *read_address, alt_u32 *write_address, alt_u32 length, alt_u32 control, alt_u16 sequence_number, alt_u8 read_burst_count, alt_u8 write_burst_count, alt_u16 read_stride, alt_u16 write_stride) |
Include: | < modular_sgdma_dispatcher.h > |
Parameters: | *dev-a pointer to msgdma instance. *descriptor – a pointer to an extended descriptor structure. *read_address – a pointer to the base address of the source memory. *write_address – a pointer to the base address of the destination memory. length – is used to specify the number of bytes to transfer per descriptor. The largest possible value can be filled in is “0Xffffffff”. control – control field. sequence_number – programmable sequence number to identify which descriptor has been sent to the host block. read_burst_count – programmable burst count between 1 and 128 and a power of 2. Setting to 0 will cause the host to use the maximum burst count instead. write_burst_count – programmable burst count between 1 and 128 and a power of 2. Setting to 0 will cause the host to use the maximum burst count instead. read_stride – programmable transfer stride. The stride value determines by how many words the host will increment the address. For fixed addresses the stride value is 0, sequential it is 1, ever other word it is 2, etc… write_stride – programmable transfer stride. The stride value determines by how many words the host will increment the address. For fixed addresses the stride value is 0, sequential it is 1, every other word it is 2, etc… |
Returns: | “0” for success, -EINVAL for invalid argument, could be due to argument which has larger value than hardware setting value.
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Description: | Helper functions for constructing mm_to_st, st_to_mm, mm_to_mm extended descriptors. Unnecessary elements are set to 0 for completeness and will be ignored by the hardware. |