Clock Frequency Accuracy Measurement Circuit (Cac); Overview - Renesas RX100 Series User Manual

RX13T Group
10.

Clock Frequency Accuracy Measurement Circuit (CAC)

10.1

Overview

The clock frequency accuracy measurement circuit (CAC) counts pulses of the clock to be measured (measurement
target clock) within the time generated by the clock to be used as a measurement reference (measurement reference
clock), and determines the accuracy depending on whether the number of pulses is within the allowable range.
When measurement is completed or the number of pulses within the time generated by the measurement reference clock
is not within the allowable range, an interrupt request is generated.
Table 10.1 lists the specifications of the CAC and Figure 10.1 shows a block diagram of the CAC.
Table 10.1 CAC Specifications
Item
Measurement target clocks
Measurement reference clocks
Selectable function
Interrupt sources
Low power consumption function
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
10. Clock Frequency Accuracy Measurement Circuit (CAC)
Description
The frequency of the following clocks can be measured.
 Main clock
 HOCO clock
 LOCO clock
 IWDT-dedicated clock (IWDTCLK)
 Peripheral module clock B (PCLKB)
 External clock input to the CACREF pin
 Main clock
 HOCO clock
 LOCO clock
 IWDT-dedicated clock (IWDTCLK)
 Peripheral module clock B (PCLKB)
Digital filter function
 Measurement end interrupt
 Frequency error interrupt
 Overflow interrupt
Module stop state can be set.
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