Data Fields
uint16_t	FrameReference

uint16_t	FrameLength

uint32_t	FrameSendOffset

uint16_t	FrameId

uint8_t	FrameFlags1

uint8_t	FrameIndex

uint16_t	RR

uint16_t	Phase

Field Documentation

◆ FrameReference

uint16_t t_ppmDesc::FrameReference

Lower 16 bit of byte address for the PPM buffer. It includes offset for current triple buffer.

◆ FrameLength

uint16_t t_ppmDesc::FrameLength

11 bits of frame length, set by host only. Frame length has total number of bytes without 4 bytes of CRC which are generated by hardware. Bit 12 to 15 must be 0. Used by PRU to fill in cycle counter and status towards the end of frame.

◆ FrameSendOffset

uint32_t t_ppmDesc::FrameSendOffset

Send in RED period: FSO as provided by engineering and limited to 22 bits, i.e. 4.1ms. Set by host only. Higher bits must be set to 0. FSO =0 indicates green phase packet.

◆ FrameId

uint16_t t_ppmDesc::FrameId

FrameID as provided by engineering. Not used for PPM.

◆ FrameFlags1

uint8_t t_ppmDesc::FrameFlags1

TODO

◆ FrameIndex

uint8_t t_ppmDesc::FrameIndex

Index is already considered in FrameReference. Used by host which first reads BufferLock register to get the ppm# and then looks up descriptor to read FrameIndex currently used

◆ RR

uint16_t t_ppmDesc::RR

Reduction Ratio for red period is in (RR-1) where RR is 1,2,4,8,16. Reduction Ration for green period is (RR-1) where RR is 1,2 ,4 …512.

◆ Phase

uint16_t t_ppmDesc::Phase

used for sendlist generation. Phase starts from 1 .. RR

Data Fields