AD73422BB-80 Analog Devices Inc, AD73422BB-80 Datasheet - Page 24

• Manufacturer Part Number: AD73422BB-80
• Manufacturer: Analog Devices Inc

Specifications of AD73422BB-80

• Single Supply Voltage (typ): 3.3V
• Single Supply Voltage (min): 3V
• Single Supply Voltage (max): 3.6V
• Package Type: BGA
• Lead Free Status / RoHS Status: Not Compliant

AD73422
The IRQ2, IRQ0 and IRQ1 input pins can be programmed to
be either level- or edge-sensitive. IRQL0 and IRQL1 are level-
sensitive and IRQE is edge-sensitive. The priorities and vector
addresses of all interrupts are shown in Table XX.
Source of Interrupt
RESET (or Power-Up with PUCR = 1) 0000 (Highest Priority)
Power-Down (Nonmaskable)
IRQ2
IRQL1
IRQL0
SPORT0 Transmit
SPORT0 Receive
IRQE
BDMA Interrupt
SPORT1 Transmit or IRQ1
SPORT1 Receive or IRQ0
Timer
Interrupt routines can either be nested with higher priority
interrupts taking precedence or processed sequentially. Inter-
rupts can be masked or unmasked with the IMASK register.
Individual interrupt requests are logically ANDed with the bits
in IMASK; the highest priority unmasked interrupt is then
selected. The power-down interrupt is nonmaskable.
The AD73422 masks all interrupts for one instruction cycle
following the execution of an instruction that modifies the
IMASK register. This does not affect serial port autobuffering
or DMA transfers.
The interrupt control register, ICNTL, controls interrupt nest-
ing and defines the IRQ0, IRQ1 and IRQ2 external interrupts to
be either edge- or level-sensitive. The IRQE pin is an external
edge-sensitive interrupt and can be forced and cleared. The
IRQL0 and IRQL1 pins are external level-sensitive interrupts.
The IFC register is a write-only register used to force and clear
interrupts. On-chip stacks preserve the processor status and are
automatically maintained during interrupt handling. The stacks
are twelve levels deep to allow interrupt, loop and subroutine
nesting. The following instructions allow global enable or dis-
able servicing of the interrupts (including power-down), regard-
less of the state of IMASK. Disabling the interrupts does not
affect serial port autobuffering or DMA.
ENA INTS;
DIS INTS;
When the processor is reset, interrupt servicing is enabled.
LOW POWER OPERATION
The AD73422 has three low power modes that significantly
reduce the power dissipation when the device operates under
standby conditions. These modes are:
• Power-Down
• Idle
• Slow Idle
The CLKOUT pin may also be disabled to reduce external
power dissipation.
Table XX. Interrupt Priority and Interrupt Vector Addresses
Interrupt Vector
Address (Hex)
0004
0008
000C
0018
0020
0024
0028 (Lowest Priority)
002C
0010
0014
001C
–24–
Power-Down
The AD73422 processor has a low power feature that lets the
processor enter a very low power dormant state through hard-
ware or software control. Here is a brief list of power-down
features. Refer to the ADSP-2100 Family User’s Manual, Third
Edition, “System Interface” chapter, for detailed information
about the power-down feature.
• Quick recovery from power-down. The processor begins
• Support for an externally generated TTL or CMOS proces-
• Support for crystal operation includes disabling the oscillator
• Power-down is initiated by either the power-down pin (PWD)
• Context clear/save control allows the processor to continue
• The RESET pin also can be used to terminate power-down.
• Power-down acknowledge pin indicates when the processor
Idle
When the AD73422 is in the Idle Mode, the processor waits
indefinitely in a low power state until an interrupt occurs. When
an unmasked interrupt occurs, it is serviced; execution then
continues with the instruction following the IDLE instruction.
In Idle Mode IDMA, BDMA and autobuffer cycle steals still
occur.
Slow Idle
The IDLE instruction on the AD73422 slows the processor’s
internal clock signal, further reducing power consumption. The
reduced clock frequency, a programmable fraction of the normal
clock rate, is specified by a selectable divisor given in the IDLE
instruction. The format of the instruction is
where n = 16, 32, 64 or 128. This instruction keeps the proces-
sor fully functional, but operating at the slower clock rate. While
it is in this state, the processor’s other internal clock signals,
such as SCLK, CLKOUT and timer clock, are reduced by the
same ratio. The default form of the instruction, when no clock
divisor is given, is the standard IDLE instruction.
When the IDLE (n) instruction is used, it effectively slows
down the processor’s internal clock and thus its response time to
incoming interrupts. The one-cycle response time of the stan-
dard idle state is increased by n, the clock divisor. When an
enabled interrupt is received, the AD73422 will remain in the
idle state for up to a maximum of n processor cycles (n = 16, 32,
64 or 128) before resuming normal operation.
executing instructions in as few as 400 CLKIN cycles.
sor clock. The external clock can continue running during
power-down without affecting the 400 CLKIN cycle recovery.
to save power (the processor automatically waits 4096 CLKIN
cycles for the crystal oscillator to start and stabilize), and
letting the oscillator run to allow 400 CLKIN cycle start up.
or the software power-down force bit. Interrupt support
allows an unlimited number of instructions to be executed
before optionally powering down. The power-down interrupt
also can be used as a nonmaskable, edge-sensitive interrupt.
where it left off or start with a clean context when leaving the
power-down state.
has entered power-down.
IDLE (n);
REV. 0