IPCBuffer

Overview

Buffer data between instances through shared heap

Discussion

IPCBuffer routes all input wire data to a user-defined instance ID. All of the downstream modules connected to the output pin will inherit the instance ID configured by the user. This module requires the configuration and initialization of the AWECore shared heap on all instances of a target. Designs including IPCBuffer will fail to build without the existence of shared heap.

IPCBuffer allows a user to select the instance ID to which all input pin data will route to using the parameter targetInstance. IPCBuffer does not modify the input data in any way, but instead handles the IPC layer routing through AWECore's shared heap, to provide an abstracted multi-instance design interface.

The module supports multiple input and output pins. The input wires must all be on the same clock divider, but they can all have different block sizes, sample rates, and data types.

The module optionally allows you to increase or decrease the clock divider by an integer factor (bufferUpDownFactor). This causes the output block size to increase or decrease by bufferUpDownFactor as well. That means, if bufferUpDownFactor > 0 the output clock divider and block size increased by bufferUpDownFactor and if bufferUpDownFactor < 0 then the output clock divider and block size decreased by bufferUpDownFactor. If bufferUpDownFactor == 0 then the output clock divider and block size inherited from the input pin Larger clock dividers end up going into lower priority layouts.

The module also optionally allows you to specify the output layoutSubID. The layoutSubID allows you to run multiple sets of modules at the same clockDivider but in different layouts. For example, you might have multiple layouts all at a clock divider of 1 operating in a SMP core system. When using Designer, layoutSubID is selected in a droplist to be 'A' to 'P' which corresponds to 16 unique layouts. When using Matlab scripts, layoutSubID is an integer in the range [0 15] which maps directly to [A P]. If layoutSubID is empty, then the thread ID is inherited from the input pin.

Layouts are specified using a combination of bufferUpDownFactor and layoutSubID. The system input pin is always in layout 1A. The system output pin can be on any of the clockDivider 1 layouts (1A, 1B, etc.). If you want multiple layouts all at the same block time as the input pin, then select 1B, 1C, and so forth.

This module introduces a sample latency equal to the bufferUpDownFactor times input pin's block size if bufferUpDownFactor > 0 and input pin's block size otherwise.

Note: This module is released as a beta feature, and may change in incompatible ways in future releases

Type Definition

-- Not Shown --

Pins

Input Pins

Name: in1

Description: audio input

Data type: {float, int, fract32}

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real and Complex

Output Pins

Name: out1

Description: audio output

Data type: {float, int, fract32}

MATLAB Usage

File Name: ipc_buffer_subsystem.m

SYS = ipc_buffer_subsystem(NAME, NUMPINS, TARGETINSTANCE)
 Creates an IPC audio module which occupies shared memory, allowing for 
 multi-instance audio buffer sharing to abstract IPC audio routing.
    NAME - name of the module.
    NUMPINS - number of pins on input and output
    TARGETINSTANCE - the output layout can run on a different coreID than the
    input layout. TARGETINSTANCE specifies which instanceID layout the IPCFifoOut
    buffer will be processed from.
       By default, TARGETINSTANCE=0.
    BUFFER_UP_DOWN_FACTOR - the output instance can run at a larger or smaller clock divider
       (block size) compared to the input instance.  BUFFER_UP_DOWN_FACTOR is the
       multiplicative or divisor factor which connects the input and output:
       If BUFFER_UP_DOWN_FACTOR is > 0:
           outputBlockSize = inputBlockSize * BUFFER_UP_DOWN_FACTOR
           outputClockDivider = inputClockDivider * BUFFER_UP_DOWN_FACTOR
       If BUFFER_UP_DOWN_FACTOR < 0:
           outputBlockSize = inputBlockSize / abs(BUFFER_UP_DOWN_FACTOR)
           outputClockDivider = inputClockDivider / abs(BUFFER_UP_DOWN_FACTOR)
       By default, BUFFER_UP_DOWN_FACTOR=0 which inherits properties from input to output.
    LAYOUT_SUB_ID - allows you to specify which sublayout ID will be used to process
       the output clockDivider.  By default, this is empty which indicates that
       the ID from input is inherited to output. The sublabel is an integer in the range [0 15] which
       provides finer control over which layout to join.  By default,
       LAYOUT_SUB_ID=[], which causes inherit from input.
   Note: This module is released as a beta feature, and may change in incompatible ways in future releases