Reconfigurable half-precision floating-point real/complex fused multiply and add unit

Multiplication followed by an addition/subtraction is the common operation in many digital signal and image processing applications. This paper presents a reconfigurable floating-point real/complex fused multiply and add (R/C-FMA) unit using small precision (IEEE-754-2008 16-bit half-precision) format. The developed FMA can be reconfigurable from real to complex based on the control bits. This architecture performs real FMA [(a x b) + c], complex FMA {[(a + ib) x (c + id)] + (e + if)} or mixed real and complex FMA {[(a + ib) x (c + id)] + e}. The field programmable gate array (FPGA) implementation of R/C-FMA design, utilises the modern features of inbuilt DSP blocks for mantissa multiplication and addition/subtraction. The efficient DSP usage for fp16 FMA design shows a 60% reduction in LUT area when compared to conventional fp32 FMA.