The power consumption by the data cache is important in DSP designs. This study presents an enhanced branch access LRU-SEQ (EBA-LRU-SEQ) policy for data caches in DSP designs to reduce the power consumption. The design is based on the LRU policy with embedded prefetch table to provide branch access. Tests show that the EBA-LRU-SEQ policy reduces the data cache power consumption to 54% of a system with no power control.

An ultra-low power complementary metal-oxide-semiconductor (CMOS) front-end readout ASIC was developed for a portable digital radiation detector. The ASIC having a charge sensitive amplifier and a semi-Gaussian pulse-shaper was produced using the CSMC 0.5 μm DPDM process. The ENC noise of 363 e at 0 pF with a noise slope of 23 e/pF complies with the stringent low noise requirements. The peaking time was 250 ns at a 100 mV/fC conversion gain (detector capacitance is 20 pF). By operating this front-end readout ASIC in the weak inversion region, the ultra-low power dissipation is only 0.1 mW/channel (3.0 V). Simulations and test results suggest that this design gives lower power consumption than the front-end readout ASICs working in the strong inversion and is appropriate for the portable digital radiation detectors.