Variable Precision DSP Blocks User Guide: Agilex™ 5 FPGAs and SoCs

ID 813968
Date 9/20/2024
Public
Document Table of Contents

3.2.2.4. Sum of Two FP16 Multiplication with Accumulation Mode

This mode performs a summation of two half-precision multiplication and accumulate the value into single-precision format:

fp32_result(t) = [fp16_mult_top_a(t) * fp16_mult_top_b(t)] + [fp16_mult_bot_a(t) * fp16_mult_bot_b(t)] + fp32_result(t-1)

The following are exception flags supported in flushed and bfloat16 formats:
  • fp16_mult_top_invalid
  • fp16_mult_top_inexact
  • fp16_mult_top_overflow
  • fp16_mult_top_underflow
  • fp16_mult_bot_invalid
  • fp16_mult_bot_inexact
  • fp16_mult_bot_overflow
  • fp16_mult_bot_underflow
  • fp16_adder_invalid
  • fp16_adder_inexact
  • fp16_adder_overflow
  • fp16_adder_underflow
  • fp32_adder_invalid
  • fp32_adder_inexact
  • fp32_adder_overflow
  • fp32_adder_underflow
The following are exception flags supported in extended format:
  • fp16_mult_top_invalid
  • fp16_mult_top_inexact
  • fp16_mult_top_infinite
  • fp16_mult_top_zero
  • fp16_mult_bot_invalid
  • fp16_mult_bot_inexact
  • fp16_mult_bot_infinite
  • fp16_mult_bot_zero
  • fp16_adder_invalid
  • fp16_adder_inexact
  • fp16_adder_infinite
  • fp16_adder_zero
  • fp32_adder_invalid
  • fp32_adder_inexact
  • fp32_adder_overflow
  • fp32_adder_underflow
Figure 40. Sum of Two FP16 Multiplication with Accumulation Mode