EVAL-ADE7816EBZ AD [Analog Devices], EVAL-ADE7816EBZ Datasheet - Page 31

• Manufacturer Part Number: EVAL-ADE7816EBZ
• Description: Six Current Channels, One Voltage Channel
• Manufacturer: AD [Analog Devices]

Data Sheet
OUTPUTS
This section describes the outputs from the ADE7816.
INTERRUPTS
The
managed by a 32-bit interrupt mask register, MASK0 and MASK1
(Address 0xE50A and Address 0xE50B), respectively. To enable
an interrupt, a bit in the MASKx register must be set to 1. To
disable an interrupt, the bit must be cleared to 0. Two 32-bit
status registers, STATUS0 and STATUS1 (Address 0xE502 and
Address 0xE503, respectively), are associated with the interrupts.
When an interrupt event occurs in the
sponding flag in the interrupt status register is set to a Logic 1
(see
the interrupt mask register is Logic 1, the
active low. The flag bits in the interrupt status register are set,
irrespective of the state of the mask bits. To determine the source
of the interrupt, the microcontroller must perform a read of the
corresponding STATUSx register and identify which bit is set to 1.
To erase the flag in the status register, write back to the STATUSx
register with the flag set to 1. After an interrupt pin goes low, the
status register is read and the source of the interrupt is identified.
Then, the status register is written back, with no changes, to
clear the status flag to 0. The IRQx pin remains low until the
status flag is cancelled.
By default, all interrupts are disabled, with the exception of
the RSTDONE interrupt. This interrupt can never be masked
(disabled) and, therefore, Bit 15 (RSTDONE) in the MASK1
register does not have any functionality. The IRQ1 pin always
goes low, and Bit 15 (RSTDONE) in the STATUS1 register is set
to 1 whenever a power-up or a hardware/software reset process
ends. To cancel the RSTDONE status flag, the STATUS1 register
nust be written with Bit 15 (RSTDONE) set to 1.
COMMUNICATION
Serial Interface Selection
After reset, the HSDC port is always disabled. Choose between the
I
or after a hardware reset. If the SS /HSA pin is held high, the
ADE7816
If the
or after a hardware reset, the
new hardware reset is executed. This manipulation of the
pin can be accomplished in two ways. The first option is to use
the SS /HSA pin of the master device (that is, the microcontroller)
as a regular I/O pin and toggle it three times. The second option is
to execute three SPI write operations to a location in the address
space that is not allocated to a specific
Address 0xEBFF, where 8-bit writes can be executed).
2
C and SPI ports by manipulating the SS /HSA pin after power-up
ADE7816
Table 30
SS /HSA pin is toggled high to low three times after power-up
uses the I
and
has two interrupt pins, IRQ0 and IRQ1 . Each pin is
Table 31
2
C port until a new hardware reset is executed.
). If the mask bit for this interrupt in
ADE7816
ADE7816
ADE7816
uses the SPI port until a
IRQx logic output goes
register (such as
, the corre-
SS /HSA
Rev. 0 | Page 31 of 48
These writes allow the SS /HSA pin to toggle three times. See the
SPI Write Operation section for details on the write protocol
that is involved.
After the serial port choice is completed, it must be locked.
If I
register (Address 0xEC01) must be set to 1 to lock it in. From then
on, the
and an eventual switch to use of the SPI port is no longer possible.
If the SPI is the active serial port, any write to the CONFIG2
register locks the port. From then on, a switch to the I
longer possible.
The functionality of the
registers. The contents of these registers can be updated or read,
using either the I
instantaneous values of the voltages and current channels.
I
The
interface is implemented as a full hardware slave. SDA is the data
I/O pin, and SCL is the serial clock. These two pins are shared with
the MOSI and SCLK pins, respectively, of the on-chip SPI interface.
The maximum serial clock frequency supported by this interface is
400 kHz.
The SDA and SCL pins are used for data transfer and are con-
figured in a wire-AND’ e d format that allows arbitration in a
multimaster system.
The transfer sequence of an I
initiating a transfer by generating a start condition while the bus
is idle. The master transmits the address of the slave device and the
direction of the data transfer in the initial address transfer. If the
slave acknowledges, the data transfer is initiated. This continues
until the master issues a stop condition and the bus becomes idle.
I
The write operation, using the I
initiated when the master generates a start condition, consists
of one byte representing the address of the ADE7816, followed
by the 16-bit address of the target register and by the value of
the register.
The most significant seven bits of the address byte constitute
the address of the ADE7816, which is 0111000b. Bit 0 of the
address byte is a read/ write bit. Because this is a write operation,
it must be cleared to 0; therefore, the first byte of the write
operation is 0x70. After every byte is received, the
generates an acknowledge. The register can be 8, 16, or 32 bits
in length. After the last bit of the register is transmitted and the
ADE7816
condition. The addresses and the register content are sent with
the most significant bit first. See
write operation.
2
2
C-Compatible Interface
C Write Operation
2
C is the active serial port, Bit 1 (I2C_LOCK) of the CONFIG2
ADE7816
ADE7816
acknowledges the transfer, the master generates a stop
supports a fully licensed I
2
C or SPI interfaces. The HSDC port provides the
ignores spurious toggling of the SS /HSA pin,
ADE7816
2
C system consists of a master device
2
C interface of the ADE7816,
Figure 39
is accessible via several on-chip
2
C interface. The I
for details of the I
ADE7816
ADE7816
2
C port is no
2
C
2
C