SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
Configure the reference clock to measure the frequency of on-chip oscillators. The reference clock source is configurable by DDI_0_OSC:CTL0.ACLK_REF_SRC_SEL, as listed in Table 20-23.
ACLK_REF_SRC_SEL | Oscillator | Frequency (kHz) |
---|---|---|
0x0 | RCOSC_HF | 31.25 |
0x1 | XOSC_HF | 31.25 |
0x2 | RCOSC_LF | 32 |
0x3 | XOSC_LF | 32.786 |
0x4 | RCOSC_MF | 2000 |
0x5–0x7 | Not Used | Not applicable |
Configuration of DDI_0_OSC:CTL0.ACLK_REF_SRC_SEL is done through the DDI Control-Configuration interface. For details, see Section 20.4.1.1.
The user must activate the selected reference clock source before a TDC measurements can start:
The user must deactivate any requests from high-frequency oscillators when the TDC measurements are complete. Failure to do so will prevent the system from entering standby mode because the Oscillator Control module requests resources from the supply system. Clear AUX_SYSIF:TDCREFCLKCTL.REQ to remove clock source request.