Mike Pleasance (National Research Council of Canada) Brent Carlson (National Research Council of Canada) Thushara Gunaratne (National Research Council of Canada) Michael Rupen (National Research Council of Canada) Sonja Vrcic (National Research Council of Canada) Topic: EC TALON Frequency Slice Architecture Correlator / Beamformer for SKA1 Mid We present the driving correlator / beamfomer requirements for the Square Kilometer Array Mid Telescope and the NRC led design produced during the pre-construction phase for the SKA project. We also report prototyping progress made during the pre-construction phase and outline the next steps for the SKA1 Mid Correlator / Beamformer (Mid.CBF). The Mid.CBF system must be able to handle data from any of six SKA1 Bands and generate a variety of data products including visibility sets and tied-array beams for pulsar search, pulsar timing and VLBI. SKA sub-arraying requirement demand that the array can be partitioned into 16 sub-arrays, with each sub-array operating in a different band and generating different types of output products. Further, strict constraints are placed on the cost, power consumption and physical footprint of the Mid.CBF system. The NRC design for the Mid.CBF utilizes the NRC generated Frequency Slice Architecture to partition the system into two parts. The VCC-Part contains all per-antenna signal processing and generates outputs which are distributed to the FSP-Part. The VCC-Part contains all Band dependent processing allowing the FSP-Part to perform correlation and beamforming for all sub-arrays regardless of the Band a particular sub-array is observing. Further, the FSP-Part is comprised on re-configurable Frequency Slice Processors (FSP) which can configured to perform one of four "function modes", Correlation, PSS Beamforming, PST Beamforming and VLBI Beamforming. Using re-configurable FSPs allows optimization of the amount of hardware deployed for Mid.CBF by providing enough compute resources to provide full commensality of correlation and beamforming in lower SKA bands