• Generates an interrupt if the interrupt is enabled.
• Requests that each enabled sensor stores the number of ring oscillator pulses that it receives during
the measurement window.
• Restarts the PVT counters after the sensors have stored the measurements.
The reference counter has the following operating modes:
• One-shot mode: Performs a single measurement and then waits.
• Repeat mode: Repeats the measurements until controls signals stop them or the system is powered
down.
Counter
The counters count and store the number of ring oscillator output pulses that they receive during the
measurement window:
• The CTRL_ENABLE Register generates an enable signal for each sensor.
• The reference counter synchronizes the sensor counter measurement process.
• Each sensor counter has its own flags:
— Sample flags to indicate that a new measurement value is ready.
— Overflow to indicate that the sensor counter has reached
0xFFFF_FFFF
. The overflow flag stays
HIGH until the reference counter initiates a new measurement.
Ring oscillators
The ring oscillators consist of 501 inverting stages and the PVT sensor control registers can enable or
disable them. The ring oscillators are built from different inverting cells, NOT, NAND, and NOR gates to
represent the main cells that are available. The following table shows the ring oscillators with their
sensor ID, voltage domain, and location on the die.
Table C-1 PVT ring oscillators
Sensor ID Cell
Voltage domain
0
inv_svt_c50 1V1
1
inv_lvt_c40
2
inv_svt_c40
Controlling and reading data from the PVT sensors
The PVT sensor control registers control and read data from the active PVT sensor. See
C PVT sensors
C.1 PVT sensors
101835_0000_01_en
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