ADE7953ACPZ datasheet(51/68 Pages) AD

51 / 68 page

Data Sheet

ADE7953

Rev. A | Page 51 of 68

COMMUNICATING WITH THE ADE7953

All ADE7953 features can be accessed via a group of on-chip

registers. For a detailed list of all the registers, see the ADE7953

Registers section. Three different communication interfaces can

be used to access the on-chip registers.

•

4-pin SPI interface

•

2-pin bidirectional I2C interface

•

2-pin UART interface

All three communication options use the same group of pins

and, therefore, only one method of communication should be

used in each design.

COMMUNICATION AUTODETECTION

The ADE7953 contains a detection system that automatically

detects which of the three communication interfaces is being

used. This feature allows communication to be quickly estab-

lished with minimal initialization. Autodetection works by

monitoring the status of the four communication pins and

automatically selecting the communication interface that

matches the configuration (see Table 9).

•

The CS pin (Pin 28) is used to determine whether the

communication method is SPI. If this pin is held low, the

communication interface is set to SPI.

•

The SCLK pin (Pin 25) is used to determine whether the

communication method is I2C or UART. If this pin is held

high, the communication interface is set to I2C; if it is held

low, the communication interface is set to UART.

Therefore, although Pin 25 (SCLK) and Pin 28 (CS) are not

required if communicating via I2C or UART, these pins should

be configured in hardware as shown in Table 9 to ensure the

functionality of the autodetection system.

LOCKING THE COMMUNICATION INTERFACE

After the selected communication interface is established, the

interface should be locked to prevent the communication

method from inadvertently changing. The ADE7953 can be

configured to lock automatically after the first successful

communication.

The automatic lock feature is disabled by default and is enabled

by clearing the COMM_LOCK bit (Bit 15) in the CONFIG

communication interface, a write should be issued shortly after

power-up to the CONFIG register, clearing the COMM_LOCK

bit and thus locking the communication interface. When the

communication interface is locked to a specific method (that is,

SPI, I2C, or UART), the communication method cannot be

changed without resetting the ADE7953.

Note that if using the SPI communication interface to lock

the communication mode, the CS pin must be held low for a

minimum of 1.2 μs after the last SCLK. This delay is required

only when writing to the COMM_LOCK bit (see the SPI

Interface Timing section).

Table 9. Communication Autodetection

Communication Interface

Pin 28 (CS)

Pin 25 (SCLK)

Pin 27 (MOSI/SCL/Rx)

Pin 26 (MISO/SDA/Tx)

SPI

Don’t care

MOSI

MISO

I2C

SCL

SDA

UART

ADE7953ACPZ 数据表(PDF) 51 Page - Analog Devices

ADE7953ACPZ 数据表(HTML) 51 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