在SRAM的datasheet中有如下内容，翻译一下：biasing level adjust input.its setting gives a smaller value of rise on vss-core voltage to give enough head room for retention.this setting is recommendde for Vnom.

"biasing level adjust input.its setting gives a smaller value of rise on vss-core voltage to give enough head room for retention.this setting is recommended for Vnom." 的翻译如下：

偏置电平调整输入。其设置会在Vss-core电压上提供较小的上升值，以为保留提供足够的余量。该设置建议用于Vnom。