This register provides the Current Descriptor Pointer for the AXI CDMA Scatter Gather Descriptor Management.
| Bits | Field Name | Default Value | Access Type | CDMA Mode Used | Description |
|---|---|---|---|---|---|
| 31 to 6 | Current Descriptor Pointer | 0 |
R/W (RO) |
SG | Current Descriptor Pointer. Indicates the pointer of the
current descriptor being worked on. This register must contain a pointer to a valid
descriptor prior to writing to the TAILDESC_PTR register. Failure to do so results
in an undefined operation by the CDMA. When the CDMA SG Engine is running (CDMASR.IDLE = 0), the CURDESC_PNTR register is updated by the SG Engine to reflect the starting address of the current descriptor being executed. On error detection, the CURDESC_PNTR register is updated to reflect the descriptor associated with the detected error. The register must only be written by the software application when the AXI CDMA is idle (CDMASR.IDLE = 1). Descriptor addresses written to this field must be aligned to 64-byte boundaries (sixteen 32-bit words). Examples are 0x00, 0x40, 0x80. For 64byte alignment bits [5:0] must be 0. Any other alignment has undefined results. This register is cleared when CDMACR.SGMode = 0. |
| 5 to 0 | Reserved | 0 | RO | N/A | Writing to these bits has no effect and they are always read as zeros. |
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