The format of the Basic command word is shown in Figure 1 and detailed in Table 1.
Note: * = S2MM or MM2S
Figure 1. DataMover Basic Command Word Layout
| Bits | Field Name | Description |
|---|---|---|
| (N+39) – (N+36) 1 | RSVD | Reserved: This field is reserved to pad the command width to an even multiple of 8 bits. (required for AXI4-Stream interfaces) |
| (N+35) – (N+32) 1 | TAG | Command TAG: You assign this field an arbitrary value to the command. The TAG flows through the DataMover execution pipe and gets inserted into the corresponding status word for the command. |
| (N+31) –32 1 | SADDR | Start Address: This field indicates the starting address to use for the memory mapped side of the transfer requested by the command. |
| 31 – 4 | Ignored | This field is ignored by the DataMover Basic. Can be any value but zeroes are recommended. |
| 23 | TYPE | TYPE: Specifies the type of AXI4 access. A value of 1 means INCR access, while a value of 0 means a FIXED address access. |
| 22 –(X+1) | Ignored | This field is ignored by the DataMover Basic. Can be any value but zeros are recommended. |
| X – 0 | BTT |
Bytes to Transfer: This field indicates the total number
of bytes to transfer for the command. The maximum allowed value is
set by the following formula: Max Burst Length x (Streaming Data width)/8 |
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