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
The TSM clock source is individually configurable for each state. The TSM can be clocked from ACLK or a high frequency clock selected with the ESICLK bit. When ESICLK = 1, ACLK is used for the state, and when ESICLK = 0, the high frequency clock is used. The high frequency clock can be sourced from SMCLK or the TSM internal oscillator, selected by the ESIHFSEL bit. The high-frequency clock can be divided by 1, 2, 4, or 8 with ESIDIV1x bits.
A set ESICLKON bit is used to turn on the selected high frequency clock source for the duration of the state, when it is not used for the state. If the DCO is selected as the high frequency clock source, it is automatically turned on, regardless of the low-power mode settings of the MSP430.
The TSM internal oscillator should be adjusted to the nominal frequency of 4.8 MHz. To realize this it can be tuned in nominal 3% steps from around 1 MHz to around 8MHz with the ESICLKFQx. The frequency and the steps differ from unit to unit. See the device-specific data sheet for parameters.
The TSM internal oscillator frequency can be measured with ACLK. When ESIHFSEL = 1 and ESICLKGON = 1 ESICNT3 is reset, and beginning with the next rising edge of ACLK, ESICNT3 counts the clock cycles of the internal oscillator. ESICNT3 counts the internal oscillator cycles for one ACLK period. Reading ESICNT3 while it is counting will result in reading 01h.
The ACLK is automatically turned on for the following cases, regardless of the low-power mode settings of the MSP430: