71M6534 datasheet(96/132 Pages) MAXIM | Exceeds IEC 62053/ANSI C12.20 Standards

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71M6533/G/H and 71M6534/H Data Sheet

FDS_6533_6534_004

Rev 2

5.3.4 Environment

Before starting the CE using the CE_E bit, the MPU has to establish the proper environment for the CE by

implementing the following steps:

•

Load the CE data into RAM.

•

Establish the equation to be applied in EQU[2:0].

•

Establish the accumulation period and number of samples in PRE_SAMPS[1:0] and SUM_CYCLES[5:0].

•

Establish the number of cycles per ADC multiplexer frame (MUX_DIV[3:0]).

•

Apply proper values to SLOTn_SEL[3:0] and SLOTn_ALTSEL[3:0].

•

Set PLS_INTERVAL[7:0] to 81.

•

Select the proper values for FIR_LEN[1:0] (1) and MUX_DIV[3:0] (6).

•

Set CHOP_E[1:0] = 00.

•

Initialize any MPU interrupts, such as CE_BUSY, XFER_BUSY, or a power failure detection interrupt.

When different CE codes are used, a different set of environment parameters needs to be established.

The exact values for these parameters are stated in the Application Notes and other documentation

accompanying the CE codes.

Operating CE codes with environment parameters deviating from the values specified will lead to

unpredictable results.

Typically, there are thirteen 32768 Hz cycles per ADC multiplexer frame (see Figure 19 in the System

Timing Summary section). This means that the product of the number of cycles per frame and the number

of conversions per frame must be 12 (allowing for one settling cycle). The default configuration is FIR_LEN

= 1 (two cycles per conversion) and MUX_DIV[3:0] = 6 (6 conversions per mux cycle).

During operation, CHOP_E[1:0] = 00 enables the automatic chopping mode and forces an alternate

multiplexer sequence at regular intervals. This enables accurate temperature measurement.

71M6534 Datasheet(PDF) 96 Page - Maxim Integrated Products