Microsemi SmartFusion2 MSS User manual

SmartFusion2, IGLOO2, and RTG4
Hard Multiplier Accumulator Configuration

SmartFusion2, IGLOO2, and RTG4 Hard Multiplier Accumulator Configuration
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Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1 SmartDesign. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Core Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Port Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
A Product Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Customer Technical Support Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Website . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Contacting the Customer Technical Support Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
ITAR Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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Introduction
The Hard Multiplier Accumulator for SmartFusion2, IGLOO2, and RTG4 supports normal (Figure 1) and
dot product (Figure 2) multiplication. Blue registers indicate control signals; brown registers are for data.
Key Features
The Hard Multiplier Accumulator supports two operating modes: Normal and Dot Product.
• A structural netlist is generated in either Verilog or VHDL
• Individual inputs and outputs can be optionally registered with:
– A common rising edge clock
– Independent active-low asynchronous and synchronous clear controls
– Independent active-high enable controls
• An additional cascade output CDOUT can be enabled. This is the sign-extended 44 bit copy of
output P
• An additional Carry In input can be enabled
Figure 1 • Normal Multiplier Accumulator
Figure 2 • Dot Product Multiplier Accumulator

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• An additional Carry Out or Overflow output can be enabled.
• Normal Mode Features:
– Configurable operand widths for A0 and B0 between 2 and 18
– Configurable operand width for C between 2 and 44
– Optional assignment of operand A0 to an 18 bit two's complement constant
– Optional assignment of operand C to a 44 bit two’s complement constant
– Option to select between Multiplier followed by Adder, Subtractor or dynamic AddSub
– Optional Arithmetic Right Shift by 17 bits of the feedback input
• Dot Product Mode Features:
– Configurable operand widths for A0, B0, A1, B1 between 2 and 9.
– Configurable operand width for C between 2 and 35.
– Optional assignment of operand A0 and A1 to a 9 bit two's complement constant
– Optional assignment of Operand C to a 35 bit two’s complement constant

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1 – SmartDesign
The Hard Multiplier Accumulator for SmartFusion2, IGLOO2, and RTG4 is available for download from
the Libero® SoC IP Catalog via the web repository. Once listed in the Catalog you can double-click the
macro to configure it in SmartDesign. For information on using SmartDesign to configure, connect, and
generate cores, see the Libero SoC online help.
Figure 1-1 • Hard Multiplier Accumulator Configuration Options - Normal Mode

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After configuring and generating the macro instance, you can simulate basic functionality. The macro can
then be instantiated as a component of a larger design.
Figure 1-2 • Hard Multiplier Accumulator Configuration Options - Dot Product Mode

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2 – Core Parameters
Table 2-1 lists the Normal mode Hard Multiplier Accumulator settings; Table 2-2 lists the Dot Product
mode settings.
Table 2-1 • Hard Multiplier Accumulator Normal Mode Configuration Description
Name Valid Range Description
Multiplier Functions
Function Multiplier
Accumulator
(Adder)
Multiplier
Accumulator
(Subtractor)
Multiplier
Accumulator
(Adder/Subtractor)
The Multiplier Accumulator with Adder/Subtractor exposes the SUB
control signal, which enables you to dynamically toggle between an
add or subtract operation.
Input Port A0
Use Constant Sets input port A0 to constant
Constant Value (Hex) -217 to (217 - 1) Two's complement value of A0, if A0 is constant. Values shorter than
18 bits are padded with zeros. Negative values must be a full 18 bits
wide. For example, 0x1FFFF means +131071 (217 - 1), while 0x3FFFF
means -1
Width 2 to 18 Width of input port A0; if shorter than 18 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1
Register Port Registers input port A0 (if A0 is not set to constant)
Input Port B0
Width 2 to 18 Width of input port B0; if shorter than 18 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Register Port Registers input port B0
Input Port C
Use Constant Sets input port C to constant
Constant Value (Hex) -243 to (243 - 1) Two's complement value of C, if C is constant. Values shorter than 44
bits are padded with zeros. Negative values must be a full 44 bits wide.
Width 2 to 44 Width of input port C; if shorter than 44 bits it is sign-extended. For
example, If the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Carry In Carry in for C (if C is not set to constant)

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Register Port Registers input port C and Carry In (if C is not set to constant)
Input Port ARSHFT17
Right Shift of
Feedback Input Feedback input is arithmetic right-shifted by 17 if selected
Register Port Registers ARSHFT17 control signal
Input Port SUB
Register Port Registers control input port SUB when Multiplier Accumulator with
Adder/Subtractor option is selected
Output Port P
Register Port Always Selected Registers output port P, CDOUT and Overflow/CarryOut
Overflow/CarryOut None, Overflow,
CarryOut Select the output port function to include in the module interface
Table 2-1 • Hard Multiplier Accumulator Normal Mode Configuration Description (continued)
Name Valid Range Description
Table 2-2 • Hard Multiplier Accumulator Dot Product Mode Configuration Description
Name Valid Range Description
Input Port A0
Use Constant Sets input port A0 to constant
Constant Value (Hex) -28to (28- 1) Two's complement value of A0, if A0 is constant. Values shorter than 9
bits are padded with zeros. Negative values must be a full 9 bits wide.
For example, 0xFF means +255 (28- 1), while 0x1FF means -1
Width 2 to 9 Width of input port A0; if shorter than 9 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Register Port Registers input port A0 (if A0 is not set to constant)
Input Port A1
Use Constant Sets input port A1 to constant
Constant Value (Hex) -28to (28- 1) Two's complement value of A1, if A1 is constant. Values shorter than 9
bits are padded with zeros. Negative values must be a full 9 bits wide.
For example, 0xFF means +255 (28- 1), while 0x1FF means -1
Width 2 to 9 Width of input port A1; if shorter than 9 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Register Port Registers input port A1 (if A1 is not set to constant)
Input Port B0

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Width 2 to 9 Width of input port B0; if shorter than 9 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Register Port Registers input port B0
Input Port B1
Width 2 to 9 Width of input port B1; if shorter than 9 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Register Port Registers input port B1
Input Port C
Use Constant Sets input port C to constant
Constant Value (Hex) -235 to (235 - 1) Two's complement value of C, if C is constant. Values shorter than 35
bits are padded with zeros. Negative values must be a full 35 bits wide.
Width 2 to 35 Width of input port C; if shorter than 35 bits it is sign-extended. For
example, if the width is 8, a value of 0x7F means +127 and a value of
0xFF means -1.
Carry In Carry in for C (if C is not set to constant)
Register Port Registers input port C and Carry In (if C is not set to constant)
Output Port P
Register Port Always selected Registers output port P, CDOUT, and Overflow/CarryOut
Overflow/CarryOut None, Overflow,
CarryOut Select the output port function to include in the module interface
Table 2-2 • Hard Multiplier Accumulator Dot Product Mode Configuration Description
Name Valid Range Description

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3 – Port Description
The figures below display the Hard Multiplier Accumulator input and output ports for Normal mode
(Figure 3-1) and Dot Product mode (Figure 3-2). Only a subset of the ports is used in any given Hard
Multiplier Accumulator configuration.
Figure 3-1 • Hard Multiplier Accumulator Ports, Normal Mode
Figure 3-2 • Hard Multiplier Accumulator Ports, Dot Product Mode