olo_base_tdm_mux¶
Status Information¶
VHDL Source: olo_base_tdm_mux
Description¶
This component allows selecting one unique channel over a bunch of "N" time division multiplexed (tdm, see Conventions) data. Note that the number of channels must be compile-time defined (i.e. the entity does not support variable number of channels at run-time).
The select signal In_ChSel is sampled when the data of the first channel of a TDM burst arrives. The output Out_Data/Out_Valid is asserted after the last channel of a TDM burst was received.
The state of the In_ChSel signal in between the CH0 inputs (where it is sampled) does not have any effect as depicted by the figure below.
The entity does automatically synchronize the channel counter to In_Last. However, it can also be used in absence of In_Last. In this case the first sample after reset is interpreted as channel 0 and the channel-counter is freerunning.
If In_Last is asserted on the last channel in a TDM burst, the corresponding output hast Out_Last asserted (independently of which channel was selected). This behavior allows to signal packet-boundaries throughout the olo_base_tdm_mux.
Generics¶
| Name | Type | Default | Description |
|---|---|---|---|
| Width_g | positive | - | Data-width |
| Channels_g | positive | - | Number of TDM channels on the input side |
Interfaces¶
Control¶
| Name | In/Out | Length | Default | Description |
|---|---|---|---|---|
| Clk | in | 1 | - | Clock |
| Rst | in | 1 | - | Reset input (high-active, synchronous to Clk) |
Input Data¶
| Name | In/Out | Length | Default | Description |
|---|---|---|---|---|
| In_Data | in | Width_g | - | Input data |
| In_Valid | in | 1 | '1' | AXI4-Stream handshaking signal for In_Data |
| In_Last | in | 1 | '0' | AXI4-Stream Last signal. Can be used to signal the last channel in TDM bursts or packet boundaries (but must be asserted on the last input channel in this case). |
| In_ChSel | in | in | - | Channel select. Samples together with channel 0 data on In_Data |
Output Data¶
| Name | In/Out | Length | Default | Description |
|---|---|---|---|---|
| Out_Data | out | Width_g | N/A | Output data |
| Out_Valid | out | 1 | N/A | AXI4-Stream handshaking signal for Out_Data |
| Out_Last | out | 1 | N/A | AXI4-Stream Last signal (used for signaling packet boundaries) |
Architecture¶
The architecture of the entity is simple, not detailed description is required.