Complex Multiplier 6.0 - 2022.1 English

Vitis Model Composer User Guide (UG1483)

Document ID
UG1483
Release Date
2022-05-26
Version
2022.1 English

The Complex Multiplier block implements AXI4-Stream compliant, high-performance, optimized complex multipliers for devices based on user-specified options.

The two multiplicand inputs and optional rounding bit are input on independent AXI4-Stream channels as slave interfaces and the resulting product output using an AXI4-Stream master interface.

Within each channel, operands, and the results are represented in signed two’s complement format. The operand widths. and the result width are parameterizable.

Block Parameters

Page 1 tab
Parameters specific to the Basic tab are:
Channel A Options
Has TLAST
Adds a tlast input port to the A channel of the block.
Has TUSER
Adds a tuser input port to the A channel of the block.
TUSER Width
User defined, maximum Limit range (1, 256).
Channel B Options
Has TLAST
Adds a tlast input port to the B channel of the block.
Has TUSER
Adds a tuser input port to the B channel of the block.
TUSER Width
User defined. maximum Limit range (1, 256).
Multiplier Construction Options
Use_Mults
Use embedded multipliers/XtremeDSP slices.
Use_LUTs
Use LUTs in the fabric to construct multipliers.
Optimization Goal
Only available if Use_Mults is selected.
Resources
Uses the 3-real-multiplier structure. However, a 4-real-multiplier structure is used when the 3- l- multiplier structure uses more multiplier resources.
Performance
Always uses the 4-real multiplier structure to allow the best frequency performance to be achieved.
Flow Control Options
Blocking
Selects “Blocking” mode. In this mode, the lack of data on one input channel does block the execution of an operation if data is received on another input channel.
NonBlocking
Selects “Non-Blocking” mode. In this mode, the lack of data on one input channel does not block the execution of an operation if data is received on another input channel.
Page 2 tab
Output Product Range

Select the output bit width. The values are automatically set to provide the full-precision product when the A and B operand widths are set. The output is sign-extended if required.

The natural output width for complex multiplication is (APortWidth + BPortWidth + 1). When the Output Width is set to be less than this, the most significant bits of the result are those output; the remaining bits will either be truncated or rounded according to Output Rounding option selected. That is to say, the output MSB is now fixed at (APortWidth + BPortWidth). For details please refer to the document LogiCORE IP Complex Multiplier v6.0 Product Guide.

Output Rounding
If rounding is required, the Output LSB must be greater than zero.
Truncate
Truncate the output.
Random_Rounding
When this option is selected, a ctrl_tvalid and ctrl_tdata input port is added to the block. Bit 0 if ctrl_tdata input determines the particular type if rounding for the operation. For details, refer to the Rounding section of the Complex Multiplier LogiCORE IP Product Guide (PG104).
Channel CTRL Options
The following options are activated when Random Rounding is selected.
Has TLAST
Adds a ctrl_tlast input port to the block.
Has TUSER
Adds a ctrl_user input port to the block.
TUSER Width
Specifies the bit width of the ctrl_tuser input port.
Output TLAST Behavior
Determines the behavior of the dout_tlast output port.
Null
Output is null.
Pass_A_TLAST
Pass the value of the a_tlast input port to the dout_tlast output port.
Pass B_TLAST
Pass the value of the b_tlast input port to the dout_tlast output port.
Pass CTRL_TLAST
Pass the value of the ctrl_tlast input port to the dout_tlast output port.
OR_all_TLASTS
Pass the logical OR of all the present TLAST input ports.
AND_all_TLASTS
Pass the logical AND of all the present TLAST input ports.
Core Latency
Latency Configuration
Automatic
Block latency is automatically determined by Model Composer by pipelining the underlying LogiCORE™ for maximum performance.
Manual
You can adjust the block latency specifying the minimum block latency.
Minimum Latency
Entry field for manually specifying the minimum block latency.
Control Signals
ACLKEN
Enables the clock enable (aclken) pin on the core. All registers in the core are enabled by this control signal.
ARESETn
Active-Low synchronous clear input that always takes priority over ACLKEN. A minimum ARESETn active pulse of two cycles is required, since the signal is internally registered for performance. A pulse of one cycle resets the core, but the response to the pulse is not in the cycle immediately following.
Advanced tab
Block Icon Display
Display shortened port names
On by default. For example, when unchecked, dout_tvalid becomes m_axis_dout_tvalid.

LogiCORE™ Documentation

Complex Multiplier LogiCORE IP Product Guide (PG104)