ADSP-2189NKSTZ-320 View Datasheet(PDF) - Analog Devices
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ADSP-2189NKSTZ-320 Datasheet PDF : 48 Pages
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ADSP-218xN
MODES OF OPERATION
The ADSP-218xN series modes of operation appear in Table 2.
Table 2. Modes of Operation
Mode D Mode C Mode B Mode A Booting Method
X
0
0
0
BDMA feature is used to load the first 32 program memory words from the byte memory
space. Program execution is held off until all 32 words have been loaded. Chip is
configured in Full Memory Mode.1
X
0
1
0
No automatic boot operations occur. Program execution starts at external memory
location 0. Chip is configured in Full Memory Mode. BDMA can still be used, but the
processor does not automatically use or wait for these operations.
0
1
0
0
BDMA feature is used to load the first 32 program memory words from the byte memory
space. Program execution is held off until all 32 words have been loaded. Chip is
configured in Host Mode. IACK has active pull-down. (Requires additonal hardware.)
0
1
0
1
IDMA feature is used to load any internal memory as desired. Program execution is held
off until the host writes to internal program memory location 0. Chip is configured in
Host Mode. IACK has active pull-down.1
1
1
0
0
BDMA feature is used to load the first 32 program memory words from the byte memory
space. Program execution is held off until all 32 words have been loaded. Chip is
configured in Host Mode; IACK requires external pull-down. (Requires additonal
hardware.)
1
1
0
1
IDMA feature is used to load any internal memory as desired. Program execution is held
off until the host writes to internal program memory location 0. Chip is configured in
Host Mode. IACK requires external pull-down.1
1 Considered as standard operating settings. Using these configurations allows for easier design and better memory management.
Setting Memory Mode
Memory Mode selection for the ADSP-218xN series is made
during chip reset through the use of the Mode C pin. This pin is
multiplexed with the DSP’s PF2 pin, so care must be taken in
how the mode selection is made. The two methods for selecting
the value of Mode C are active and passive.
Passive Configuration
Passive Configuration involves the use of a pull-up or pull-
down resistor connected to the Mode C pin. To minimize power
consumption, or if the PF2 pin is to be used as an output in the
DSP application, a weak pull-up or pull-down resistance, on the
order of 10 kΩ, can be used. This value should be sufficient to
pull the pin to the desired level and still allow the pin to operate
as a programmable flag output without undue strain on the pro-
cessor’s output driver. For minimum power consumption
during power-down, reconfigure PF2 to be an input, as the pull-
up or pull-down resistance will hold the pin in a known state,
and will not switch.
Active Configuration
Active Configuration involves the use of a three-statable exter-
nal driver connected to the Mode C pin. A driver’s output
enable should be connected to the DSP’s RESET signal such that
it only drives the PF2 pin when RESET is active (low). When
RESET is deasserted, the driver should be three-state, thus
allowing full use of the PF2 pin as either an input or output. To
minimize power consumption during power-down, configure
the programmable flag as an output when connected to a three-
stated buffer. This ensures that the pin will be held at a constant
level, and will not oscillate should the three-state driver’s level
hover around the logic switching point.
IDMA ACK Configuration
Mode D = 0 and in host mode: IACK is an active, driven signal
and cannot be “wire-OR’ed.” Mode D = 1 and in host mode:
IACK is an open drain and requires an external pull-down, but
multiple IACK pins can be “wire-OR’ed” together.
INTERRUPTS
The interrupt controller allows the processor to respond to the
eleven possible interrupts and reset with minimum overhead.
ADSP-218xN series members provide four dedicated external
interrupt input pins: IRQ2, IRQL0, IRQL1, and IRQE (shared
with the PF7–4 pins). In addition, SPORT1 may be reconfig-
ured for IRQ0, IRQ1, FI, and FO, for a total of six external
interrupts. The ADSP-218xN also supports internal interrupts
from the timer, the byte DMA port, the two serial ports, soft-
ware, and the power-down control circuit. The interrupt levels
are internally prioritized and individually maskable (except
power-down and reset). 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 3.
Rev. A | Page 5 of 48 | August 2006
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