SLASEB7 Data sheet

SLASEB7D June 2017 – December 2020

PRODUCTION DATA

9.5.1 Peripherals in Low-Power Modes

Peripherals can be in different states that affect the achievable power modes of the device. The states depend on the operational modes of the peripherals (see Table 9-2). The states are:

A peripheral is in a "high-frequency state" if it requires or uses a clock with a "high" frequency of more than 50 kHz.
A peripheral is in a "low-frequency state" if it requires or uses a clock with a "low" frequency of 50 kHz or less.
A peripheral is in an "unclocked state" if it does not require or use an internal clock.

If the CPU requests a power mode that does not support the current state of all active peripherals, the device does not enter the requested power mode, but it does enter a power mode that still supports the current state of the peripherals, except if an external clock is used. If an external clock is used, the application must use the correct frequency range for the requested power mode.

Table 9-2 Peripheral States

PERIPHERAL	IN HIGH-FREQUENCY STATE⁽¹⁾	IN LOW-FREQUENCY STATE⁽²⁾	IN UNCLOCKED STATE⁽³⁾
WDT	Clocked by SMCLK	Clocked by ACLK	Not applicable
DMA⁽⁴⁾	Not applicable	Not applicable	Waiting for a trigger
RTC_C	Not applicable	Clocked by LFXT	Not applicable
LCD_C	Not applicable	Clocked by ACLK or VLOCLK	Not applicable
Timer_A, TAx	Clocked by SMCLK or clocked by external clock >50 kHz	Clocked by ACLK or clocked by external clock ≤50 kHz	Clocked by external clock ≤50 kHz
Timer_B, TBx	Clocked by SMCLK or clocked by external clock >50 kHz	Clocked by ACLK or clocked by external clock ≤50 kHz	Clocked by external clock ≤50 kHz
eUSCI_Ax in UART mode	Clocked by SMCLK	Clocked by ACLK	Waiting for first edge of START bit
eUSCI_Ax in SPI master mode	Clocked by SMCLK	Clocked by ACLK	Not applicable
eUSCI_Ax in SPI slave mode	Clocked by external clock >50 kHz	Clocked by external clock ≤50 kHz	Clocked by external clock ≤50 kHz
eUSCI_Bx in I²C master mode	Clocked by SMCLK or clocked by external clock >50 kHz	Clocked by ACLK or clocked by external clock ≤50 kHz	Not applicable
eUSCI_Bx in I²C slave mode	Clocked by external clock >50 kHz	Clocked by external clock ≤50 kHz	Waiting for START condition or clocked by external clock ≤50 kHz
eUSCI_Bx in SPI master mode	Clocked by SMCLK	Clocked by ACLK	Not applicable
eUSCI_Bx in SPI slave mode	Clocked by external clock >50 kHz	Clocked by external clock ≤50 kHz	Clocked by external clock ≤50 kHz
ADC12_B	Clocked by SMCLK or by MODOSC	Clocked by ACLK	Waiting for a trigger
REF_A	Not applicable	Not applicable	Always
COMP_E	Not applicable	Not applicable	Always
CRC⁽⁵⁾	Not applicable	Not applicable	Not applicable
MPY⁽⁵⁾	Not applicable	Not applicable	Not applicable
AES⁽⁵⁾	Not applicable	Not applicable	Not applicable

(1) Peripherals are in a state that requires or uses a clock with a "high" frequency of more than 50 kHz

(2) Peripherals are in a state that requires or uses a clock with a "low" frequency of 50 kHz or less.

(3) Peripherals are in a state that does not require or does not use an internal clock.

(4) The DMA always transfers data in active mode but can wait for a trigger in any low-power mode. A DMA trigger during a low-power mode causes a temporary transition into active mode for the time of the transfer.

(5) This peripheral operates during active mode only and will delay the transition into a low-power mode until its operation is completed.