Texas Instruments TMS3320C5515 Table 1-45. RTCPMGT Register Bit Descriptions Field Descriptions

System Configuration and Control

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Table 1-45. RTCPMGT Register Bit Descriptions Field Descriptions

Bit Field Value Description

15-5 Reserved 0 Reserved.Read-only, writes have no effect.

4 WU_DOUT Wakeupoutput, active low/open-drain.

0 WAKEUPpin driven low.

1 WAKEUPpin is in high-impedance (Hi-Z).

3 WU_DIR Wakeuppin direction control.

0 WAKEUPpin configured as a input.

1 WAKEUPpin configured as a output.

Note:When the WAKEUP pin is configured as an input, it is active high. When the WAKEUP pin is

configuredas an output, is an open-drain that is active low and should be externally pulled-up via a

10-kΩresistorto DVDDRTC. WU_DIR must be configured as an input to allow the WAKEUP pin to

wakethe device up from idle modes.

2 BG_PD Bandgap,on-chip LDOs, and the analog POR power down bit.

Thisbit shuts down the on-chip LDOs (ANA_LDO, DSP_LDO, and USB_LDO), the Analog POR,

andBandgap reference. BG_PD and LDO_PD are only intended to be used when the internal

LDOssupply power to the chip. If the internal LDOs are bypassed and not used then the BG_PD

andLDO_PD power down mechanisms should not be used since POR gets powered down and the

POWERGOODsignal is not generated properly.

Afterthis bit is asserted, the on-chip LDOs, Analog POR, and the Bandgap reference can be

re-enabledby the WAKEUP pin (high) or the RTC alarm interrupt. The Bandgap circuit will take

about100 msec to charge the external 0.1 uF capacitor via the internal 326-kΩresistor.

0 On-chipLDOs, Analog POR, and Bandgap reference are enabled.

1 On-chipLDOs, Analog POR, and Bandgap reference are disabled (shutdown).

1 LDO_PD On-chipLDOs and Analog POR power down bit.

Thisbit shuts down the on-chip LDOs (ANA_LDO, DSP_LDO, and USB_LDO) and the Analog

POR.BG_PD and LDO_PD are only intended to be used when the internal LDOs supply power to

thechip. If the internal LDOs are bypassed and not used then the BG_PD and LDO_PD power

downmechanisms should not be used since POR gets powered down and the POWERGOOD

signalis not generated properly.

Afterthis bit is asserted, the on-chip LDOs and Analog POR can be re-enabled by the WAKEUP

pin(high) or the RTC alarm interrupt. This bit keeps the Bandgap reference turned on to allow a

fasterwake-up time with the expense power consumption of the Bandgap reference.

0 On-chipLDOs and Analog POR are enabled.

1 On-chipLDOs and Analog POR are disabled (shutdown).

0 RTCCLKOUTEN Clockoutoutput enable bit

0 Clockoutput disabled

1 Clockoutput enabled

64 SystemControl SPRUFX5A–October 2010 –Revised November 2010

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