ADE9000 Technical Reference Manual
UG-1098
Rev. 0 | Page 43 of 86
INTERRUPTS/EVENT
The
has three pins, IRQ0, IRQ1, and CF4/EVENT/
DREADY, which can be used as interrupts to the host processor.
The IRQ0 and IRQ1 pins go low when an enabled interrupt
occurs and stay low until the event is acknowledged by setting
the corresponding status bit in the STATUS0 and STATUS1
registers, respectively. The EVENT function, which is
multiplexed with the CF4 and DREADY options on the
CF4/EVENT/DREADY pin, tracks the state of the enabled
signals and goes low and high with these internal signals. The
EVENT function is useful for measuring the duration of events,
such as dips or swells, externally.
INTERRUPTS (IRQ0 AND IRQ1)
The IRQ0 and IRQ1 pins are managed by 32-bit interrupt mask
registers, MASK0 and MASK1, respectively. Every event that
can generate an interrupt has a corresponding bit in the MASK0
or MASK1 register and the STATUS0 or STATUS1 register.
To enable an interrupt, set the corresponding bit in the
MASK0 or MASK1 register to 1. To disable an interrupt, the
corresponding bit in the MASK0 or MASK1 register must be
cleared to 0.
The STATUS0 and STATUS1 registers indicate if an event that
can generate an interrupt has occurred. If the corresponding bit
in the MASK0 or MASK1 register is set, an interrupt is generated
on the corresponding IRQ0 or IRQ1 pin, and the pin goes low.
To determine the source of the interrupt, read the
corresponding STATUS0 or STATUS1 register and identify
which enabled bits are set to 1. To acknowledge the event and
clear bits in the STATUSx register, write to the STATUSx
register with the desired bit positions set to 1. Then the
corresponding IRQ0 or IRQ1 pin goes high.
For example, if a zero-crossing occurs on the Phase A voltage
input and the ZXVA bit is set in the MASK1 register, the IRQ1
pin goes low, indicating that an enabled event has occurred. To
acknowledge the event, write a 1 to the ZXVA bit in the
STATUS1 register, and then the IRQ1 pin goes low. The ZXVA
STATUS1 bit is set regardless of whether the ZXVA bit is
enabled in MASK1.
There are a few interrupts that are nonmaskable, meaning that
they are generated even if the corresponding bit in the MASKx
register is 0. These nonmaskable interrupts include RSTDONE
and ERROR0.
There is an option to combine all the interrupts onto a single
interrupt pin, IRQ1, instead of using two pins, IRQ0 and IRQ1.
To activate this option, set the IRQ0_ON_IRQ1 bit in the
CONFIG1 register. Note that the IRQ0 pin still indicates the
enabled IRQ0 events while in this mode, and IRQ1 indicates
both IRQ1 and IRQ0 events.
The meaning of each individual interrupt source is provided in
the related data sheet section; refer to these sections in the
data sheet for more information.
EVENT
The EVENT function is multiplexed with CF4 and DREADY on
the CF4/EVENT/DREADY pin. To enable the EVENT function
to be output on this pin, write CF4_CFG = 10 in the CONFIG1
register.
There are 16 signals that can be incorporated into the EVENT
pin and are selected in the EVENT_MASK register. All of these
events sources are maskable and disabled by default.
The logic level of the EVENT output is solely dependent on the
enabled events; it cannot be changed by the user. If any of the 16
events are enabled by setting their corresponding mask bit to 1
in the EVENT_MASK register, the EVENT pin goes low
whenever one of the enabled events occurs and stays low until
all the enabled signals have gone high. Then, the EVENT pin
goes high. Note that the status sources used to generate the
EVENT are not latched; if one event source is selected, the
EVENT pin tracks the status of that source.
STATUS BITS IN ADDITIONAL REGISTERS
Several interrupts are used in conjunction with other status
registers.
Overcurrent
The OI bit in the MASK1 register works in conjunction with the
OIPHASE status bits in the OISTATUS register.
No Load
The VAFNOLOAD, RFNOLOAD, AFNOLOAD, VANLOAD,
RNLOAD, and ANLOAD bits in the MASK1 register work in
conjunction with additional status bits in the PHNOLOAD register.
The following bits in the MASK0 register work with the status
bits in the PHSIGN register: REVAPx, REVRPx, and REVPSUMx.
Read the additional registers to obtain more information when
the corresponding bits are set in the STATUSx register.