ADSP-2184L/ADSP-2185L/ADSP-2186L/ADSP-2187L
Rev. C
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Page 5 of 48
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January 2008
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 (ADSP-2187L Only)
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-218xL 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-218xL 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
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.
Table 2. Modes of Operation
Mode D
1
Mode C
Mode B
Mode A
Booting Method
X
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.2
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
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 additional 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-do
wn.21
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 additional
hardware.)
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-do
wn.21 Mode D applies to the ADSP-2187L processor only.
2 Considered as standard operating settings. Using these configurations allows for easier design and better memory management.
Table 3. Interrupt Priority and Interrupt Vector Addresses
Source Of Interrupt
Interrupt Vector Address
(Hex)
RESET (or Power-Up with PUCR = 1) 0x0000 (highest priority)
Power-Down (Nonmaskable)
0x002C
IRQ2
0x0004
IRQL1
0x0008
IRQL0
0x000C
SPORT0 Transmit
0x0010
SPORT0 Receive
0x0014
IRQE
0x0018
BDMA Interrupt
0x001C
SPORT1 Transmit or IRQ1
0x0020
SPORT1 Receive or IRQ0
0x0024
Timer
0x0028 (lowest priority)