adsp-2196m Analog Devices, Inc., adsp-2196m Datasheet - Page 13

• Manufacturer Part Number: adsp-2196m
• Description: Dsp Microcomputer
• Manufacturer: Analog Devices, Inc.

Figure 5. UART Clock Rate Calculation
1
The timers can be used to provide a hardware-assisted
autobaud detection mechanism for the UART interface.
Programmable Flag (PFx) Pins
The ADSP-2196 has 16 bidirectional, general-purpose I/O,
Programmable Flag (PF15–0) pins. The PF7–0 pins are
dedicated to general-purpose I/O. The PF15–8 pins serve
either as general-purpose I/O pins (if the DSP is connected
to an 8-bit external data bus) or serve as DATA15–8 lines
(if the DSP is connected to a 16-bit external data bus). The
Programmable Flag pins have special functions for clock
multiplier selection and for SPI port operation. For more
information, see
page 12
ory-mapped registers control operation of the
Programmable Flag pins:
• Flag Direction register
• Flag Control and Status registers
• Flag Interrupt Mask registers
• Flag Interrupt Polarity register
• Flag Sensitivity registers
REV. PrA
Where D = 1 to 65536
September 2001
Specifies the direction of each individual PFx pin as input
or output.
Specify the value to drive on each individual PFx output
pin. As input, software can predicate instruction
execution on the value of individual PFx input pins
captured in this register. One register sets bits, and one
register clears bits.
Enable and disable each individual PFx pin to function
as an interrupt to the DSP’s core. One register sets bits to
enable interrupt function, and one register clears bits to
disable interrupt function. Input PFx pins function as
hardware interrupts, and output PFx pins function as
software interrupts—latching in the IMASK and IRPTL
registers.
Specifies the polarity (active high or low) for interrupt
sensitivity on each individual PFx pin.
Specify whether individual PFx pins are level- or
edge-sensitive and specify—if edge-sensitive—whether
just the rising edge or both the rising and falling edges of
the signal are significant. One register selects the type of
sensitivity, and one register selects which edges are signif-
icant for edge-sensitivity.
and
UART Clock Rate
Clock Signals on page
This information applies to a product under development. Its characteristics and specifications are subject to change with-
out notice. Analog Devices assumes no obligation regarding future manufacturing unless otherwise agreed to in writing.
Serial Peripheral Interface (SPI) Ports on
=
HCLK
------------------
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For current information contact Analog Devices at 800/262-5643
D
14. Ten mem-
1
Low Power Operation
The ADSP-2196 has four low-power options that signifi-
cantly reduce the power dissipation when the device
operates under standby conditions. To enter any of these
modes, the DSP executes an IDLE instruction. The
ADSP-2196 uses configuration of the PDWN, STOPCK,
and STOPALL bits in the PLLCTL register to select
between the low-power modes as the DSP executes the
IDLE. Depending on the mode, an IDLE shuts off clocks
to different parts of the DSP in the different modes. The
low power modes are:
• Idle
• Power-Down Core
• Power-Down Core/Peripherals
• Power-Down All
Idle Mode
When the ADSP-2196 is in Idle mode, the DSP core stops
executing instructions, retains the contents of the instruc-
tion pipeline, and waits for an interrupt. The core clock and
peripheral clock continue running.
To enter Idle mode, the DSP can execute the IDLE instruc-
tion anywhere in code. To exit Idle mode, the DSP responds
to an interrupt and (after two cycles of latency) resumes
executing instructions with the instruction after the IDLE.
Power-down Core Mode
When the ADSP-2196 is in Power-Down Core mode, the
DSP core clock is off, but the DSP retains the contents of
the pipeline and keeps the PLL running. The peripheral bus
keeps running, letting the peripherals receive data.
To enter Power-Down Core mode, the DSP executes an
IDLE instruction after performing the following tasks:
• Enter a power-down interrupt service routine
• Check for pending interrupts and I/O service routines
• Clear (= 0) the PDWN bit in the PLLCTL register
• Clear (= 0) the STOPALL bit in the PLLCTL register
• Set (= 1) the STOPCK bit in the PLLCTL register
To exit Power-Down Core mode, the DSP responds to an
interrupt and (after two cycles of latency) resumes executing
instructions with the instruction after the IDLE.
Power-Down Core/Peripherals Mode
When the ADSP-2196 is in Power-Down Core/Peripherals
mode, the DSP core clock and peripheral bus clock are off,
but the DSP keeps the PLL running. The DSP does not
retain the contents of the instruction pipeline.The periph-
eral bus is stopped, so the peripherals cannot receive data.
To enter Power-Down Core/Peripherals mode, the DSP
executes an IDLE instruction after performing the
following tasks:
• Enter a power-down interrupt service routine
• Check for pending interrupts and I/O service routines
ADSP-2196
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