SLAU367P October 2012 – April 2020 MSP430FR5041 , MSP430FR5043 , MSP430FR50431 , MSP430FR5847 , MSP430FR58471 , MSP430FR5848 , MSP430FR5849 , MSP430FR5857 , MSP430FR5858 , MSP430FR5859 , MSP430FR5867 , MSP430FR58671 , MSP430FR5868 , MSP430FR5869 , MSP430FR5870 , MSP430FR5872 , MSP430FR58721 , MSP430FR5887 , MSP430FR5888 , MSP430FR5889 , MSP430FR58891 , MSP430FR5922 , MSP430FR59221 , MSP430FR5947 , MSP430FR59471 , MSP430FR5948 , MSP430FR5949 , MSP430FR5957 , MSP430FR5958 , MSP430FR5959 , MSP430FR5962 , MSP430FR5964 , MSP430FR5967 , MSP430FR5968 , MSP430FR5969 , MSP430FR5969-SP , MSP430FR59691 , MSP430FR5970 , MSP430FR5972 , MSP430FR59721 , MSP430FR5986 , MSP430FR5987 , MSP430FR5988 , MSP430FR5989 , MSP430FR5989-EP , MSP430FR59891 , MSP430FR5992 , MSP430FR5994 , MSP430FR59941 , MSP430FR6005 , MSP430FR6007 , MSP430FR6035 , MSP430FR6037 , MSP430FR60371 , MSP430FR6041 , MSP430FR6043 , MSP430FR60431 , MSP430FR6045 , MSP430FR6047 , MSP430FR60471 , MSP430FR6820 , MSP430FR6822 , MSP430FR68221 , MSP430FR6870 , MSP430FR6872 , MSP430FR68721 , MSP430FR6877 , MSP430FR6879 , MSP430FR68791 , MSP430FR6887 , MSP430FR6888 , MSP430FR6889 , MSP430FR68891 , MSP430FR6920 , MSP430FR6922 , MSP430FR69221 , MSP430FR6927 , MSP430FR69271 , MSP430FR6928 , MSP430FR6970 , MSP430FR6972 , MSP430FR69721 , MSP430FR6977 , MSP430FR6979 , MSP430FR69791 , MSP430FR6987 , MSP430FR6988 , MSP430FR6989 , MSP430FR69891
22.2.10 Total Sample Size
The total number of samples that the SDHS generates can be predefined by SDHSCTL2.SMPSZ when SDHSCTL2.SMPCTLOFF = 0. The value written to SDHSCTL2.SMPSZ includes the samples skipped by SDHSCTL0.INTDLY:
- Total number of samples SDHS generates = SMPSZ + 1 (when SDHSCTL2.SMPCTLOFF = 0)
- The number of samples that can be read or transferred = SMPSZ – INTDLY + 1 (when SDHSCTL2.SMPCTLOFF = 0)
When SDHSCTL2.SMPCTLOFF = 0, the SDHS automatically stops data conversion after completing the number of samples configured in SDHSCTL2.SMPSZ. The SDHSCTL2.SMPSZ bit is ignored when SDHSCTL2.SMPCTLOFF = 1. In this case, the SDHS continues conversion until it is stopped by the trigger source. Take care when writing a value to SDHSCTL2.SMPSZ. If SDHSCTL2.SMPSZ – SDHSCTL0.INTDLY + 1 ≤ 0, no output data is generated. For example:
If SDHSCTL2.SMPSZ = 10 and SDHSCTL0.INTDLY = 2, then the number of available samples would be 10 – 2 + 1 = 9.
Figure 22-24 SDHSCTL0.AUTOSSDIS = 0, SDHSCTL2.SMPCTLOFF = 0, SDHSCTL0.INTDLY = 0, Total Sample Size is Controlled by SDHSCTL2.SMPSZ 
Figure 22-25 SDHSCTL0.AUTOSSDIS = 1, SDHSCTL2.SMPCTLOFF = 0, SDHSCTL0.INTDLY = 0, Total Sample Size is Controlled by SDHSCTL2.SMPSZ 
Figure 22-26 SDHSCTL0.AUTOSSDIS = 1, SDHSCTL2.SMPCTLOFF = 0, SDHSCTL0.INTDLY = m, Total Sample Size is Controlled by SDHSCTL2.SMPSZ When data conversion has stopped or SDHS has been powered down, 2 sample periods must pass before starting a new data conversion or turning SDHS on (see Figure 22-24 and Figure 22-25).
- SDHS output sampling period = SDHSCTL1.OSR / PLL output clock frequency (= SDHS modulator sampling frequency).
- SDHS output sampling frequency = PLL output clock frequency (= SDHS modulator sampling frequency) / SDHSCTL1.OSR.