SBASAO8 June 2025 DAC39RF20
ADVANCE INFORMATION
The following sub-sections depict each JESD204C frame format, showing how samples and tail bits are mapped to the lanes. Any lanes that are not shown in the output format tables are unused. Each table depicts exactly one frame. Tail bits are discarded and ignored by the transport layer. All diagrams are with respect to the logical lane numbers which can be arbitrarily mapped to the external physical lanes using LANE_SELn. Each depiction shows the maximum number of streams (converters) that the mode supports, but the user can configure a smaller number (see JESD_M), which may result in fewer lanes being active.
| Meaning to the Application Layer | ||||
|---|---|---|---|---|
| Notation | Description | Bypass Mode | DUC Mode | DDS-Stream Mode |
T |
Tail bits (zeros) | - | - | - |
| C0[n] | Sample for stream 0 | see DAC_SRC | DSP0 (I) | DSP0 (sdata[15:0]) |
| C1[n] | Sample for stream 1 | see DAC_SRC | DSP0 (Q) | DSP0 (sdata[31:16]) |
| C2[n] | Sample for stream 2 | - | DSP1 (I) | DSP1 (sdata[15:0]) |
| C3[n] | Sample for stream 3 | - | DSP1 (Q) | DSP1 (sdata[31:16]) |
| C4[n] | Sample for stream 4 | - | DSP2 (I) | DSP2 (sdata[15:0]) |
| C5[n] | Sample for stream 5 | - | DSP2 (Q) | DSP2 (sdata[31:16]) |
| C6[n] | Sample for stream 6 | - | DSP3 (I) | DSP3 (sdata[15:0]) |
| C7[n] | Sample for stream 7 | - | DSP3 (Q) | DSP3 (sdata[31:16]) |
| In all of the above notations, n indicates the sample number (0 to S-1). Some JESD204C modes have S=1 (one sample per stream per frame). In those cases, “[n]” is omitted in the descriptions. | ||||