Memory circuitry with write assist

Memory circuitry is provided with write assist circuitry for generating a lower power supply voltage during write operations. The write assist circuitry includes a plurality of series connected switches including a header switch and a footer switch. Header bias circuitry generates a header bias voltage and footer bias circuitry generates a footer bias voltage. The header bias voltage is an analog signal with a voltage level intermediate between the power supply voltage level and the ground voltage level. The footer bias voltage is an analog signal with a voltage level intermediate between the power supply voltage level and the ground voltage level. During write operation target bit cells to be written are supplied with the power via a current path through the header switch while these are respectively controlled by the header bias voltage and the footer bias voltage.