Compiler/AWR1642BOOST: bpmChirpCfg.constBpmVal Question

Tool/software: TI C/C++ Compiler

Hi there,

The below BPM code is for the AWR1642. I have a question for the BpmVal. I understand how =0U means 0 unsigned (so 0deg phase shift). But, what does =0xCU mean? 0xC in hex is 12 in decimal and 1100 in binary. How does TI get 180 degrees phase shift from that 0xCU BpmVal? Thank you!

George

            /*configure chirp 0 (++)*/
            memset ((void *)&bpmChirpCfg, 0, sizeof(rlBpmChirpCfg_t));
            bpmChirpCfg.chirpStartIdx = gMmwMssMCB.cliCfg[subframe].bpmCfg.chirp0Idx; 
            bpmChirpCfg.chirpEndIdx   = gMmwMssMCB.cliCfg[subframe].bpmCfg.chirp0Idx; 
            /* Phase configuration: TX0 positive, TX1 positive*/ 
            bpmChirpCfg.constBpmVal = 0U;
                        
            bpmChirpHandle = MMWave_addBpmChirp (gMmwMssMCB.ctrlHandle, &bpmChirpCfg, &errCode);
            if (bpmChirpHandle == NULL)
            {
                System_printf ("Error: Unable to add BPM cfg chirp 0. Subframe %d [Error code %d]\n",subframe, errCode);
                return -1;
            }

            /*configure chirp 1 (++)*/
            memset ((void *)&bpmChirpCfg, 0, sizeof(rlBpmChirpCfg_t));
            bpmChirpCfg.chirpStartIdx = gMmwMssMCB.cliCfg[subframe].bpmCfg.chirp1Idx; 
            bpmChirpCfg.chirpEndIdx   = gMmwMssMCB.cliCfg[subframe].bpmCfg.chirp1Idx; 
            /* Phase configuration: TX0 positive, TX1 negative*/
            bpmChirpCfg.constBpmVal = 0xCU;
            
            bpmChirpHandle = MMWave_addBpmChirp (gMmwMssMCB.ctrlHandle, &bpmChirpCfg, &errCode);
            if (bpmChirpHandle == NULL)
            {
                System_printf ("Error: Unable to add BPM cfg chirp 1. Subframe %d [Error code %d]\n",subframe, errCode);
                return -1;
            }