MSP430FR5989: Problem reading negative temperatures using the integrated temperature sensor.

Part Number: MSP430FR5989

I was checking this example: dev.ti.com/.../node

and it is working perfectly, but with negative temperatures it didn't work. It seems to be that this formula it is not good for negative temperatures. Can anyone check that?

/* Temperature Sensor Calibration-30 C */

#define CALADC12_12V_30C *((unsigned int *)0x1A1A)

/* See device datasheet for TLV table memory mapping */

/* Temperature Sensor Calibration-85 C */

#define CALADC12_12V_85C *((unsigned int *)0x1A1C)

temperatureDegC = (float)(((long)temp - CALADC12_12V_30C) * (85 - 30)) / (CALADC12_12V_85C - CALADC12_12V_30C) + 30.0f;