We propose in this paper an efficient FALCON accelerator called EFX based on a HW/SW co-design where FALCON is a post-quantum cryptographic (PQC) scheme tailored as a digital signature algorithm (DSA). Our findings reveal that FALCON exhibits unique characteristics and structures which distinguish it from other PQC-DSAs. A key finding is that, unlike its counterparts, FALCON doesn’t prioritize a single, time-consuming task; instead, it processes a variety of tasks with comparable execution times. Consequently, the conventional methods focusing on accelerating dominant few tasks, which are generally effective for other algorithms, prove less efficient for FALCON, especially concerning the minimization of the silicon area used. To overcome this, we strategically focus on the granular optimization of lower-level operations rather than on broader functional segments, aiming to boost performance while conserving hardware space. Moreover, to mitigate the potential degradation due to limitation of hardware resources, we have implemented a pipelined execution strategy for the FALCON functions and refined the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sampling function</i> –a critical task that is challenging to accelerate due to inherent sequential algorithm–enabling it to run concurrently on both software and hardware, thus reducing latency. Our hardware design, synthesized at 300 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MHz</i> using Samsung’s 28 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nm</i> and 45 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nm</i> process technologies, demonstrates superior performance in generating FALCON signatures, with a 3.58× improvement in clock cycles over an existing hardware accelerator. EFX occupies 38K <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">um</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 74K <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">um</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for 28 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nm</i> and 45 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nm</i> processes, respectively, comparatively small compared to other PQC accelerators.