An image sensor circuit includes a pixel array, a plurality of column analog-to-digital conversion (ADC) circuits, and at least two memory blocks. Each column ADC circuit is connected to receive analog pixel signals provided from corresponding pixel circuits of the pixel array, and is configured to convert the received analog pixel signals into digital pixel signals. Each memory block is connected to receive digital pixel signals provided from corresponding column ADC circuits of the plurality of column ADC circuits. At least two of the at least two memory blocks are connected to receive digital pixel signals that are provided from corresponding column ADC circuits that are located to a same side of the pixel array. Each memory block of the at least two memory blocks includes a plurality of memory cells, one or more sense amplifiers connected to the memory cells by a readout bus, and a memory controller.