M-State is a housekeeping function internal to the TAS5086. While M-State is low, the device will not accept IIC commands.
In the TAS5086 datasheet, functions such as /RESET and /PDN are shown with M-State to illustrate the time one must wait before sending IIC commands. One example would be the case where /RESET is set is set high and IIC commands sent immediately after the low to high transistion. The TAS5086 would not accept the IIC.