REV. PrG 01/03

PRELIMINARY TECHNICAL DATA

ADE7754

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ACCESSING THE ADE7754 ON-CHIP REGISTERS

All ADE7754 functionality is accessed via the on-chip registers. Each register is accessed by first writing to the

communications register and then transferring the register data. For a full description of the serial interface protocol, see Serial

Interface section of this data sheet.

Communications Register

The Communications register is an eight bit, write-only register which controls the serial data transfer between the ADE7754

and the host processor. All data transfer operations must begin with a write to the communications register. The data written

to the communications register determines whether the next operation is a read or a write and which register is being accessed.

Table VII below outlines the bit designations for the Communications register.

Table VII : Communications Register

Bit

Bit

Description

Location

Mnemonic

0 to 5

A0 to A5

The six LSBs of the Communications register specify the register for the data transfer

operation. Table VIII lists the address of each ADE7754 on-chip register.

6

RESERVED

This bit is unused and should be set to zero.

7W / R

When this bit is a logic one the data transfer operation immediately following the write to the

Communications register will be interpreted as a write to the ADE7754. When this bit is a logic

zero the data transfer operation immediately following the write to the Communications

register will be interpreted as a read operation.

DB0

W/R

A4

A3

A2

A1

A0

0

DB1

DB2

DB3

DB4

DB5

DB6

DB7

A5