SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
When the MAC is in sleep mode and the remote wake-up frame enable bit, WUPFREN, is set in the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register, the normal operation is resumed after a remote wake-up frame is received. The application writes all eight wake-up filter registers, by performing eight sequential writes to the Ethernet MAC Remote Wake-Up Frame Filter (EMACRWUFF) register. The Power Management (PMT) block supports four programmable filters that allow support of different receive frame patterns. If the incoming frame passes the address filtering of Filter Command, and if Filter CRC-16 matches the CRC of the incoming pattern, then the MAC identifies the frame as wake-up frame. The Filter Offset determines the offset from which the frame is to be examined. The Filter Byte Mask determines which bytes of the frame must be examined. The 31st bit of Byte Mask must be set to zero. The remote wake-up CRC block determines the CRC value that is compared with Filter CRC-16. The remote wake-up frame is checked only for length error, FCS error, dribble bit error, MII error, and collision. In addition, the remote wake-up frame is checked to ensure that it is not a runt frame. Even if the remote wakeup frame is more than 512 bytes long, if the frame has a valid CRC value, it is considered valid. The remote wake-up frame detection is updated in the Ethernet MAC PMT Control and Status (EMACPMTCTLSTAT) register for every remote wake-up frame received. If the PMT interrupt is enabled in the Ethernet MAC Interrupt Mask (EMACIM) register, a PMT interrupt is asserted and the EMACPMTCTLSTAT register can be read to determine reception of a remote wake-up frame.