PC87366 datasheet(178/240 Pages) NSC

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11.0 Voltage Level Monitor (VLM) (Continued)

178

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Figure 35. VLM Functional Diagram

11.2.1

Voltage Measurement, Channels 0 through 10

Voltage is measured relative to 2.45*VREF.(VREF is the voltage of the VREF input, or the internal reference voltage.) The

results are output to the Read Channel Voltage (RDCHV) register associated with the channel. The voltage measured is:

Vi = 2.45*VREF *RDCHVi / 256

VSB,VDD and AVDD are internally divided by two. Therefore, the readouts are half their actual values. When external dividers

are used to scale input voltage to within the dynamic range of the A/D Converter, appropriate scale factors should be taken

into account.

VHIGH and VLOW Limits, ALARM Output, IRQ and SMI

The voltage reading is compared to two limits: VHIGH and VLOW. If the voltage reading is outside any of these limits, the

respective status bit (Channel High Limit Exceeded or Channel Low Limit Exceeded) in the VCHCFST register is set. The

status bit stays active until it is cleared by the software. An ALARM status bit in the VEVSTS0 or VEVSTS1 register is set

when the Channel High Limit Exceeded or the Channel Low Limit Exceeded bit for the respective channel is set.

SIB

A/D Converter

14:1

Analog

AD0

AD1

AD2

AD3

AD4

AD5

AD6

AD7

MUX

VLM

Clock

Divider

Clock

VIN0

AVI0

Control Logic

Status,

Data & Conﬁg

Registers

A/D

AVI6

VIN0

VIN6

AD8

AD12

AD11

AD13

VSB

VDD

AD9

VBAT

TS1

TS2

TS3

Low

High

Delay

Start

AVss

IRQ

ALARM

SMI

IRQ

ALERT

SMI

Converter

Analog

Power

3.3 V

VREF

REF

Internal

VREF

AVDD

*2.45

AD10

AVDD

VSB

Power

Overtemp

OTS

}

VLM

Config

TMS

Config

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