SLAU846B June 2023 – November 2024 MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G1519 , MSPM0G3105 , MSPM0G3105-Q1 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3505 , MSPM0G3505-Q1 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1 , MSPM0G3519
The VBOOST circuit in the PMU generates an internal VBOOST supply that is used by the analog muxes in COMPs, GPAMPs, and OPAs, if present on a device. The VBOOST circuit enables consistent analog mux performance across the external supply voltage (VDD) range.
Enabling and Disabling VBOOST
SYSCTL automatically manages the enable request for the VBOOST circuit based on the following parameters:
VBOOST is disabled by default following a SYSRST. Application software is not required to enable the VBOOST circuit prior to using the COMP, OPA, or GPAMP. When a COMP, OPA, or the GPAMP is enabled by application software, SYSCTL also enables the VBOOST circuit to support the analog peripheral.
The VBOOST circuit has a startup time requirement (12µs typical) to transition from a disabled state to an enabled state. If a COMP, OPA, or the GPAMP is enabled when VBOOST is disabled, then the corresponding analog peripheral ready status is not asserted until both the peripheral and the VBOOST circuit are ready. If the startup time of the COMP, OPA, or GPAMP is less than the VBOOST startup time, the peripheral startup time is extended to account for the VBOOST startup time.
Alternatively, application software can force the VBOOST circuit to be enabled at all times (with ANACPUMPCFG=0x2) or while in RUN or SLEEP mode (with ANACPUMPCFG=0x1) so that there is no additional startup delay when enabling a COMP, OPA, or the GPAMP. Table 2-1 gives the behavior of the ANACPUMPCFG control and corresponding application use cases.
VBOOST Control (ANACPUMPCFG) | Behavior | ||
---|---|---|---|
VAL | MODE | VBOOST Enable | Application Use Case |
0x0 | ONDEMAND | VBOOST is automatically enabled by SYSCTL only when a COMP, OPA, or the GPAMP is enabled. | This setting provides the lowest power consumption in all modes when fast startup of the COMP, OPA, or GPAMP is not critical. |
0x1 | ONACTIVE | VBOOST is forced to be enabled when the device is in RUN or SLEEP mode. VBOOST is also kept enabled in STOP or STANDBY mode if a COMP, OPA, or the GPAMP is enabled. | This setting provides low power consumption by disabling the VBOOST automatically in STOP and STANDBY modes when no peripherals requiring VBOOST are enabled. VBOOST is automatically re-enabled upon exit to RUN mode to provide fast startup of the COMP, OPA, or GPAMP in the event that application software enables a COMP, OPA, or GPAMP in RUN mode. |
0x2 | ONALWAYS | VBOOST is forced to be enabled in all operating modes except SHUTDOWN. | This setting makes sure that the COMP, OPA, and GPAMP never incur additional startup latency due to VBOOST startup in applications where fast COMP, OPA, or GPAMP startup is critical. |
The VBOOST enable, VBOOST clock selection, and VBOOST clock error logic is shown in Figure 2-5.
VBOOST Clock
The VBOOST circuit requires a functional clock to operate. VBOOST is clocked by either the SYSOSC (4MHz output) or the LFCLK (32kHz) based on the currently active MCLK and ULPCLK tree source. The VBOOST clock is selected by automatically by SYSCTL according to the logic shown in Figure 2-5 and described here:
Certain VBOOST operating conditions require that the VBOOST clock be 4MHz (sourced from SYSOSC) and not 32kHz (sourced from LFCLK). Such conditions include:
The application software must make sure that MCLK and ULPCLK are not sourced from LFCLK when either of these conditions are present. SYSCTL does not change the current system clock configuration for a VBOOST request. If the MCLK and ULPCLK tree is sourced from LFCLK in one of these scenarios, SYSCTL asserts an ANACLKERR status in the SYSSTATUS register in SYSCTL to indicate to application software that there is a mismatch between the VBOOST clock requirement and the current MCLK and ULPCLK configuration.
The complete clock requirements for VBOOST are given in Table 2-2.
VBOOST Request | VBOOST Circuit Clock Requirement | MCLK and ULPCLK Source Requirement(1) | Supported Operating Modes or Policies | |
---|---|---|---|---|
No active request (VBOOST is disabled) | N/A | Don't care | Don't care | |
VBOOST is starting up from a disabled state | 4MHz | Not LFCLK | RUN0, SLEEP0, STOP0, STOP1 | |
OPA enabled | 4MHz | Not LFCLK | RUN0, SLEEP0, STOP0, STOP1 | |
COMP enabled | Fast mode (FAST) | 4MHz | Not LFCLK | RUN0, SLEEP0, STOP0, STOP1 |
Ultra-low-power mode (ULP)(2) | 4MHz or 32kHz | Don't care | RUN0, RUN1, RUN2, SLEEP0, SLEEP1, SLEEP2, STOP0, STOP1, STOP2, STANDBY0 | |
GPAMP enabled(2) | 4MHz or 32kHz | Don't care | RUN0, RUN1, RUN2, SLEEP0, SLEEP1, SLEEP2, STOP0, STOP1, STOP2, STANDBY0 | |
VBOOST running with no peripheral request active (due to ANACPUMPCFG!=0x0)(2) | 4MHz or 32kHz | Don't care | RUN0, RUN1, RUN2, SLEEP0, SLEEP1, SLEEP2, STOP0, STOP1, STOP2, STANDBY0 |