  Initial access in millimeter-wave (mmW) wireless is critical toward
successful realization of the fifth-generation (5G) wireless networks and
beyond. Limited bandwidth in existing standards and use of phase-shifters in
analog/hybrid phased-antenna arrays (PAA) are not suited for these emerging
standards demanding low-latency direction finding. This work proposes a
reconfigurable true-time-delay (TTD) based spatial signal processor (SSP) with
frequency-division beam training methodology and wideband beam-squint less data
communications. Discrete-time delay compensated clocking technique is used to
support 800~MHz bandwidth with a large unity-gain bandwidth ring-amplifier
(RAMP)-based signal combiner. To extensively characterize the proposed SSP
across different SSP modes and frequency-angle pairs, an automated testbed is
developed using computer-vision techniques that significantly speeds up the
testing progress and minimize possible human errors. Using seven levels of
time-interleaving for each of the 4 antenna elements, the TTD SSP has a delay
range of 3.8 ns over 800 MHz and achieves unique frequency-to-angle mapping in
the beamtraining mode with nearly 12 dB frequency-independent gain in the
beamforming mode. The SSP is prototyped in 65nm CMOS with an area of 1.98mm$^2$
consuming only 29 mW excluding buffers. Further, an error vector magnitude
(EVM) of 9.8% is realized for 16-QAM modulation at a speed of 122.8 Mb/s.
