Datasheet

ADC128D818
www.ti.com SNAS483E –FEBRUARY 2010–REVISED MARCH 2013
6. Using the Interrupt Mask Register (address 03h), choose to mask or not to mask the interrupt status from
propagating to the interrupt output pin, INT.
7. Program the Limit Registers (addresses 2Ah – 39h).
8. Set the ‘START’ bit of the Configuration Register (address 00h, bit 0) to 1.
9. Set the 'INT_Clear' bit (address 00h, bit 3) to 0. If needed, program the 'INT_Enable' bit (address 00h, bit 1)
to 1 to enable the INT output.
The ADC128D818 then performs a round-robin monitoring of enabled voltage and temperature channels. The
sequence of items being monitored corresponds to locations in the Channel Readings Registers (except for the
temperature reading). Detailed descriptions of the register map can be found at the end of this datasheet.
Power On Reset (POR)
When power is first applied, the ADC128D818 performs a power on reset (POR) on several of its registers, which
sets the registers to their default values. These default values are shown in the table above or in the REGISTER
MAP section.
Registers whose default values are not shown have power on conditions that are indeterminate.
Configuration Register (address 00h)
The Configuration Register (address 00h) provides all control to the ADC128D818. After POR, the 'START' bit
(bit 0) is set low and the 'INT_Clear' bit (bit 3) is set high.
The Configuration Register has the ability to start and stop the ADC128D818, enable and disable the INT output,
and set the registers to their default values.
• Bit 0, ‘START’, controls the monitoring loop of the ADC128D818. After POR, set this bit high to start
conversion. Setting this bit low stops the ADC128D818 monitoring loop and puts the ADC128D818 in
shutdown mode; thus, reducing power consumption. Even though this bit is set low, serial bus communication
is possible with any register in the ADC128D818.
– After an interrupt occurs, the INT pin will not be cleared if the user sets this bit low.
• Bit 1, 'INT_Enable', enables the interrupt output pin, INT, when this bit is set high.
• Bit 3, 'INT_Clear', clears the interrupt output pin, INT, when this bit is set high. When this bit is set high, the
ADC128D818 monitoring function will stop. The content of the Interrupt Status Register (address 01h) will not
be affected.
• Bit 7, ‘INITIALIZATION’, accomplishes the same function as POR, that is, it initializes some of the registers to
their default values. This bit automatically clears after being set high. Setting this bit high, however, does not
reset the Channel Readings Registers (addresses 20h - 27h) and the Limit Registers (addresses 2Ah - 39h).
These registers will be indeterminate immediately after power on. If the Channel Readings Registers contain
valid conversion results and/or the Limit Registers have been previously set, they will not be affected by this
bit.
Interrupt Status Register (address 01h)
Each bit in this read-only register indicates whether the voltage reading > the voltage high limit or ≤ the voltage
low limit, or the temperature reading > the temperature high limit. For example, if "IN0 High Limit" register
(address 2Ah) were set to 2V and if IN0 reading (address 20h) were 2.56V, then bit 'IN0 Error' would be 1,
indicating that the voltage high limit has been exceeded.
Interrupt Mask Register (address 03h)
This register masks the interrupt status from propagating to the interrupt output pin, INT. For example, if bit 'IN0
Mask' = 1, then the interrupt output pin, INT, would not be pulled low even if an error event occurs at IN0.
Conversion Rate Register (address 07h)
There are three options for controlling the conversion rate. The first option is called the Low Power Conversion
Mode, where the device converts all of the enabled channels then enters shutdown mode. This process takes
approximately 728 ms to complete.
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