ML7344J datasheet(40/151 Pages) ETC2

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ML7344C/E/J

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●Data whitening function (non Wireless M-BUS standard)

ML7344 supports Data whitening function. In packet format A/B, subsequent data followed by C-field can be

processed data whitening. In packet format C, data Whitening is applied from data field. Data generated by the

following 9 bit pseudo random sequence (PN9) will be “XOR” with TX data (encoded data if Manchester or

3-out-of 6 coding is selected) before transmission. Intialization value of the PN9 generation shift register can be

defined by [WHT_INIT_H/L: B1 0x64/65] registers. PN9 polynomial can be programmed with [WHT_CFG:

B1 0x66] register.

Function

Control bit name

Data whitening setting enable

WHT_SET ([DATA_SET2: B0 0x08(0)])

Data whitening initialization value

WHT_INIT[8:0] ([WHT_INIT_H/L: B1 0x64(0)/65(7-0)])

Whitening polynomial

WHT_CFG[7:0] ([WHT_CFG: B1 0x66(7-0)])

In order to make feedback from S1 register, setting 0b1 to WHT_CFG0 ([WHT_CFG: B1 0x66(0)]). Similaly

in order to make feedback from S2 register, setting 0b1 to WHT_CFG1 ([WHT_CFG: B1 0x66(1)]). Other bits

of [WHT_CFG: B1 0x66] register has same function. Two or more bits can be also set to 0b1. Therefore any

type of PN9 polinominal can be programmed.

NOTE:

exclusive OR

Fig.5 Whitening data generation circuits

(generator polynomial: x9 + x5 + 1)

General PN9 polynomial can be defined by WHT_CFG[7:0].

PN9 polynomial

WHT_CFG[7:0]

[WHT_CFG: B1 0x66]

9 + x4 + 1

0x08

9 + x5 + 1

0x10

Whitening

data

ML7344J Datenblatt(PDF) 40 Page - List of Unclassifed Manufacturers