- 您现在的位置：买卖IC网 > Sheet目录1214 > EVAL-ADE7754EBZ (Analog Devices Inc)BOARD EVALAUTION FOR ADE7754
ADE7754
SERIAL INTERFACE
ADE7754 has a built-in SPI interface. The serial interface of
the ADE7754 is made of four signals: SCLK, DIN, DOUT,
and CS . The serial clock for a data transfer is applied at the
SCLK logic input, which has a Schmidt-trigger input structure
that allows slow rising (and falling) clock edges to be used. All
data transfer operations are synchronized to the serial clock.
Data is shifted into the ADE7754 at the DIN logic input on the
Figure 42 and Figure 43 show the data transfer sequences for a
read and write operation, respectively. On completion of a data
transfer (read or write), the ADE7754 once again enters com-
munications mode (i.e., the next instruction followed must be a
write to the communications register).
CS
SCLK
falling edge of SCLK. Data is shifted out of the ADE7754 at the
DOUT logic output on a rising edge of SCLK. The CS logic
input is the chip-select input. This input is used when multiple
devices share the serial bus. A falling edge on CS also resets the
serial interface and places the ADE7754 into communications
mode. The CS input should be driven low for the entire data
transfer operation. Bringing CS high during a data transfer
DIN
DOUT
COMMUNICATIONS REGISTER WRITE
0 0 ADDRESS
MULTIBYTE READ DATA
Figure 42. Reading Data from the ADE7754 via the
Serial Interface
operation will abort the transfer and place the serial bus in a
high impedance state. The CS logic input may be tied low if the
ADE7754 is the only device on the serial bus. However, with
CS
SCLK
COMMUNICATIONS REGISTER WRITE
CS tied low, all initiated data transfer operations must be fully
DIN
1 0
ADDRESS
MULTIBYTE WRITE DATA
completed (i.e., the LSB of each register must be transferred
because there is no other way to bring the ADE7754 back into
communications mode without resetting the entire device,
i.e., setting the RESET pin logic low).
All the ADE7754 functionality is accessible via several on-chip
registers. See Figure 41. The contents of these registers can be
updated or read using the on-chip serial interface. After power-
on or toggling the RESET pin low, or a falling edge on CS , the
ADE7754 is placed into communications mode. In communica-
tions mode, the ADE7754 expects the first communication to
be a write to the internal communications register. The data
written to the communications register contains the address and
specifies the next data transfer to be a read or a write command.
Therefore all data transfer operations with the ADE7754,
whether read or write types, must begin with a write to the
communications register.
Figure 43. Writing Data to the ADE7754 via the
Serial Interface
A data transfer is completed when the LSB of the ADE7754
register being addressed (for a write or a read) is transferred to
or from the ADE7754.
Serial Write Operation
The serial write sequence requires the following steps. With the
ADE7754 in communications mode and the CS input logic low,
a write to the communications register takes place. The MSB of
this byte transfer must be set to 1, indicating that the next data
transfer operation is a write to the register. The six LSBs of this
byte contain the address of the register to be written to. The
ADE7754 starts shifting in the register data on the next falling
edge of SCLK. All remaining bits of register data are shifted in
on the falling edge of subsequent SCLK pulses. See Figure 44.
DIN
COMMUNICATIONS REGISTER
As explained previously, the data write is initiated by a write to
DOUT
REGISTER 1
REGISTER 2
REGISTER 3
IN
OUT
IN
OUT
IN
OUT
the communications register, followed by the data. During a data
write operation to the ADE7754, data is transferred to all on-chip
registers one byte at a time. After a byte is transferred into the
serial port, there is a finite amount of time before the content of
the serial port buffer is transferred to one of the ADE7754 on-chip
registers. Although another byte transfer to the serial port can
start while the previous byte is being transferred to the destina-
tion register, this second byte transfer should not finish until at
REGISTER n-1
REGISTER n
IN
OUT
IN
OUT
least 1 μ s after the end of the previous byte transfer. This func-
tionality is expressed in the timing specification t 6 . See Figure 44.
If a write operation is aborted during a byte transfer (CS brought
high), then that byte will not be written to the destination register.
Figure 41. Addressing ADE7754 Registers via the
Communications Register
The communications register is an 8-bit write-only register. The
MSB determines whether the next data transfer operation is a
read or a write. The six LSBs contain the address of the register
to be accessed. See the Communications Register section for a
more detailed description.
Destination registers may be up to 3 bytes wide. See the Register
Descriptions section. Therefore, the first byte shifted into the
serial port at DIN is transferred to the MSB (most significant
byte) of the destination register. If the destination register is 12 bits
wide, for example, a 2-byte data transfer must take place. The
data is always assumed to be right justified; therefore, in this
case, the four MSBs of the first byte would be ignored and the four
LSBs of the first byte written to the ADE7754 would be the four
MSBs of the 12-bit word. Figure 45 illustrates this example.
–28 –
REV. 0
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
EVAL-ADE7755ZEB
BOARD EVALUATION FOR AD7755
EVAL-ADE7758ZEB
BOARD EVAL FOR AD7758
EVAL-ADE7759EBZ
BOARD EVALUATION FOR ADE7759
EVAL-ADE7762EBZ
BOARD EVALUATION FOR ADE7762
EVAL-ADE7763ZEB
BOARD EVALUATION FOR ADE7763
EVAL-ADE7816EBZ
BOARD EVALUATION FOR ADE7816
EVAL-ADE7878EBZ
BOARD EVAL FOR ADE7878
EVAL-ADE7880EBZ
BOARD EVAL FOR ADE7880
相关代理商/技术参数
EVAL-ADE7755EB
制造商:Analog Devices 功能描述:EVAL BOARD ENERGY METERINGW/PULSE OUTPUT - Bulk
EVAL-ADE7755EBZ
制造商:AD 制造商全称:Analog Devices 功能描述:Energy Metering IC with Pulse Output
EVAL-ADE7755EBZ1
制造商:AD 制造商全称:Analog Devices 功能描述:Energy Metering IC with Pulse Output
EVAL-ADE7755ZEB
功能描述:BOARD EVALUATION FOR AD7755 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:- 主要目的:电信，线路接口单元（LIU） 嵌入式:- 已用 IC / 零件:IDT82V2081 主要属性:T1/J1/E1 LIU 次要属性:- 已供物品:板，电源，线缆，CD 其它名称:82EBV2081
EVAL-ADE7756EB
制造商:Analog Devices 功能描述:EVAL BD DOCUMENTATION ADE7756 ENERGY METERING IC - Bulk 制造商:Rochester Electronics LLC 功能描述:
EVAL-ADE7757AEBZ
制造商:Analog Devices 功能描述:EVALUATION BOARDS - Bulk
EVAL-ADE7757EB
制造商:Analog Devices 功能描述:EVAL BOARD ENERGY METERINGW/PULSE OUTPUT - Bulk
EVAL-ADE7758ZEB
功能描述:BOARD EVAL FOR AD7758 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:* 标准包装:1 系列:PSoC® 主要目的:电源管理，热管理 嵌入式:- 已用 IC / 零件:- 主要属性:- 次要属性:- 已供物品:板，CD，电源