ADE7953ACPZ datasheet(57/68 Pages) AD

57 / 68 page

Data Sheet

ADE7953

Rev. A | Page 57 of 68

COMMUNICATION VERIFICATION AND SECURITY

The ADE7953 includes three security measures to increase

communication robustness and to help prevent inadvertent

modifications to its internal registers. The write protection,

communication verification, and checksum features can be used

together to help increase the robustness and noise immunity of

the meter design.

WRITE PROTECTION

The ADE7953 provides a simple method for protecting the

internal registers from unexpected write operations. This feature

helps to prevent noise or EMC conditions from changing the

required meter configuration. The write protection feature is

disabled by default to allow the meter to be configured and can

be enabled by writing to the 8-bit WRITE_PROTECT register

(Address 0x040). Only the three LSBs of this register are used.

Bit 0 controls the protection on the 8-bit registers; Bit 1 controls

the protection on the 16-bit registers; Bit 2 controls the protection

on the 24-bit/32-bit registers. All bits are set to 0 by default to

disable the protection. Setting any of these bits to 1 enables

write protection on the corresponding group of registers. When

write protection is enabled, any attempted write operation using

the SPI, I2C, or UART interface is ignored. The one exception to

this is the WRITE_PROTECT register that can still be modified

to disable the write protection feature. Resetting the WRITE_

PROTECT bits to 0 reinstates full access to the register banks.

COMMUNICATION VERIFICATION

The ADE7953 includes a set of three registers that allow any

communication via SPI, I2C, or UART to be verified. The

LAST_OP (Address 0x0FD), LAST_ADD (Address 0x1FE),

and LAST_RWDATA registers record the type, address, and

data of the last successful communication, respectively. The

LAST_RWDATA register has four separate addresses, depending

on the length of the successful communication (see Table 11).

Multiple address locations are included to prevent unnecessarily

long communications.

Table 11. Addresses of the LAST_RWDATA Registers

Length of Read/Write

Address 0x0FF

8 bits

Address 0x1FF

16 bits

Address 0x2FF

24 bits

Address 0x3FF

32 bits

After each successful communication with the ADE7953, the

address of the last register that was accessed is stored in the

16-bit LAST_ADD register (Address 0x1FE). This read-only

is complete.

The LAST_OP register (Address 0x0FD) stores the type of the

communication, that is, it indicates whether a read or a write

was performed. If the last operation was a write, the LAST_OP

the LAST_OP register stores the value 0x35.

The LAST_RWDATA register stores the data that was written to

or read from the register. Unsuccessful read and write operations

are not reflected in these registers.

ADE7953ACPZ 数据表(PDF) 57 Page - Analog Devices

ADE7953ACPZ 数据表(HTML) 57 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68

数据表下载