SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
POK modules are responsible for accurately detecting average voltage levels.
Two types of POK modules are implemented in this family of devices - POK and POK_SA.
POK module is capable of monitoring a range of supplies and indicating a failure within the programmable upper and lower threshold limits for the supply being monitored. POKs are used to monitor 3.3 V, 1.8 V and core supply levels with programmable threshold levels.
Figure 5-643 shows the concept of the POK. It is a comparator with a fixed 0.45V and the voltage to be monitored. The voltage-to-be-monitored is defined based upon a CTRL register (see POK Related Registers) and the silicon hook-up of the POK. The POK has three possible input voltage ports – VDD_MON3P3, VDD_MON1P8, and VDD_MON. The effect of the CTRL register depends upon which of these three ports is selected; for example, a threshold value of 0x28 in the threshold register would create a different threshold voltage depending upon:
The POK output triggers high (i.e. indicating a fail condition) when:
When the monitored voltage threshold is changed, the new threshold settles within 5us.
Figure 5-643 also shows a mux on the output of the comparator. The mux is configured based upon the selection of under-voltage or over-voltage and is used to maintain the proper polarity of the fail signature.
POK_SA (used only on VMON1_ER_VSYS) directly compares the monitored voltage to 0.45V.
Two other features of the POK diagram (i.e. Figure 5-643) need some explanation:
POK configuration is not designed to find and report an instantaneous dip / rise in the voltage.
POK and PRG | Voltage Monitored | Register(2) |
---|---|---|
PRG_PP_MAIN | CTRLMMR_WKUP_PRG_PP_MAIN_CTRL | |
IPOK_VDD_CORE | VDD_CORE | CTRLMMR_WKUP_POK_VDD_CORE_UV_CTRL CTRLMMR_WKUP_POK_VDD_CORE_OV_CTRL |
IPOK_VDDR_CORE | VDDAR_CORE | CTRLMMR_WKUP_POK_VDDR_CORE_UV_CTRL CTRLMMR_WKUP_POK_VDDR_CORE_OV_CTRL |
IPOK_VDD_CPU | VDD_CPU | CTRLMMR_WKUP_POK_VDD_CPU_UV_CTRL CTRLMMR_WKUP_POK_VDD_CPU_OV_CTRL |
IPOK_VMON_EXT | VDDSHV in MCU | CTRLMMR_WKUP_POK_VMON_EXT_UV_CTRL CTRLMMR_WKUP_POK_VMON_EXT_OV_CTRL |
IPOK_VMON_EXT_MAIN_1P8 | VDDSHV in MAIN | CTRLMMR_WKUP_POK_VMON_EXT_MAIN1P8_UV_CTRL CTRLMMR_WKUP_POK_VMON_EXT_MAIN1P8_OV_CTRL |
IPOK_VMON_EXT_MAIN_3P3 | VDDSHV in MAIN | CTRLMMR_WKUP_POK_VMON_EXT_MAIN3P3_UV_CTRL CTRLMMR_WKUP_POK_VMON_EXT_MAIN3P3_OV_CTRL |
PRG_PP_MCU | CTRLMMR_WKUP_PRG_PP_MCU_CTRL | |
IPOK_VDDR_MCU | VDDAR_MCU | CTRLMMR_WKUP_POK_VDDR_MCU_UV_CTRL CTRLMMR_WKUP_POK_VDDR_MCU_OV_CTRL |
IPOK_VDDSHV_WKUP_GEN | VDDSHV0_MCU | CTRLMMR_WKUP_POK_VDDSHV_WKUP_GEN_UV_CTRL CTRLMMR_WKUP_POK_VDDSHV_WKUP_GEN_OV_CTRL |
IPOK_CAP_VDDS_MCU_GEN | CAP_VDDS0_MCU | CTRLMMR_WKUP_POK_VMON_CAP_MCU_GEN_UV_CTRL CTRLMMR_WKUP_POK_VMON_CAP_MCU_GEN_OV_CTRL |
PRG_PP_POR | CTRLMMR_WKUP_PRG_PP_POR_CTRL | |
IPOK_VDD_MCU_OV(1) | VDD_MCU | CTRLMMR_WKUP_POK_VDD_MCU_OV_CTRL |
IPOK_VDDA_PMIC_IN | PMIC VSYS | CTRLMMR_WKUP_POK_VDDA_PMIC_IN_CTRL |
PRG_PP_POR | CTRLMMR_WKUP_PRG_PP_POR_CTRL CTRLMMR_WKUP_PRG_PP_POR_STAT CTRLMMR_WKUP_POR_BANDGAP_CTRL |
|
POR_POKLVB_VDD_MCU_UV | VDD_MCU UV | CTRLMMR_WKUP_POR_POKHV_UV_CTRL |
POR_POKHV_VDDA_WKUP_POR_UV | VDDA_MCU (1.8V) UV | CTRLMMR_WKUP_POR_POKLVB_UV_CTRL |
POR_POKLVA_VDDA_WKUP_POR_OV | VDDA_MCU (1.8V) OV | CTRLMMR_WKUP_POR_POKLVA_OV_CTRL |