AS39513 datasheet(22/108 Pages) AMSCO

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[v1-10] 2018-Apr-25

AS39513 − Detailed Description

The limit check algorithm is as follows. The limit result for each

sensor is computed. For each limit result that is non-zero, the

limit counter that corresponds to that limit flag is incremented.1

The over limit count flag OVLIM will be set if any of the following

conditions are true: TXHICNT > 0, TXLOCNT > 0, THICNT >

THIMAX, TLOCNT > TLOMAX, EXHICNT > 0, EXLOCNT > 0, EHICNT

> EHIMAX, or ELOCNT > ELOMAX (These System parameters are

further documented in the Memory Map section).

There are two types of limit check modes: normal and limit

crossing.

If normal limit mode is selected (LOGMD = 2’b10), then logging

will occur if, and only if, at least one of the two sensor’s limit

results is non-zero.

If limit crossing mode is selected (LOGMD = 2’b11), then logging

will occur if, and only if, the limit result for either sensor is

different from that sensor’s previous measurement limit result.

At initialization, the “previous” limit result for each sensor is

assumed to be 3’b000. Therefore, the first measurement that

will be logged will be the first time that at least one of the two

sensor’s limit results is non-zero.

If neither of the limit modes are selected (LOGMD[1] = 0), then

no limits are checked, the limit counters are not changed, and

the measurement results are always logged.

Measurement Results Logging

If one of the limit criteria are satisfied, or if the device is in the

no-limit logging mode (LOGMD = 2’b00 or 2’b01), than the

measurement results are logged.

Memory Check: Prior to writing the log values in EEPROM, the

logging measurement pointer MEASPTR[11:0] is checked to

insure that there will be room for the log data.

If there is no room and STRMD is 0, the data is not logged, and

the error flag EEFULL is set.

1. The limit counters are simple binary counters. If a limit count exceeds 16’hFFFF (65535), then the count will wrap around to zero.

AS39513 Fiches technique(PDF) 22 Page - ams AG