  We conduct a wide-band X-ray spectral analysis in the energy range of 1.5-100
keV to study the time evolution of the M7.6 class flare of 2016 July 23, with
the Miniature X-ray Solar Spectrometer (MinXSS) CubeSat and the Reuven Ramaty
High Energy Solar Spectroscopic Imager (RHESSI) spacecraft. With the
combination of MinXSS for soft X-rays and RHESSI for hard X-rays, a non-thermal
component and three-temperature multi-thermal component -- "cool" ($T \approx$
3 MK), "hot" ($T \approx$ 15 MK), and "super-hot" ($T \approx$ 30 MK) -- were
measured simultaneously. In addition, we successfully obtained the spectral
evolution of the multi-thermal and non-thermal components with a 10 s cadence,
which corresponds to the Alfv\'en time scale in the solar corona. We find that
the emission measures of the cool and hot thermal components are drastically
increasing more than hundreds of times and the super-hot thermal component is
gradually appearing after the peak of the non-thermal emission. We also study
the microwave spectra obtained by the Nobeyama Radio Polarimeters (NoRP), and
we find that there is continuous gyro-synchrotron emission from mildly
relativistic non-thermal electrons. In addition, we conducted a differential
emission measure (DEM) analysis by using Atmospheric Imaging Assembly (AIA)
onboard the Solar Dynamics Observatory (SDO) and determine that the DEM of cool
plasma increases within the flaring loop. We find that the cool and hot plasma
components are associated with chromospheric evaporation. The super-hot plasma
component could be explained by the thermalization of the non-thermal electrons
trapped in the flaring loop.
