ADSP-21062/ADSP-21062L
include interrupt generation upon completion of DMA trans-
fers and DMA chaining for automatic linked DMA transfers.
Off-Chip Memory and Peripherals Interface
The ADSP-21062’s external port provides the processor’s inter-
face to off-chip memory and peripherals. The 4-gigaword off-
chip address space is included in the ADSP-21062’s unified
address space. The separate on-chip buses—for PM addresses,
PM data, DM addresses, DM data, I/O addresses and I/O
data—are multiplexed at the external port to create an external
system bus with a single 32-bit address bus and a single 48-bit
(or 32-bit) data bus.
Serial Ports
The ADSP-21062 features two synchronous serial ports that
provide an inexpensive interface to a wide variety of digital and
mixed-signal peripheral devices. The serial ports can operate at
the full clock rate of the processor, providing each with a maxi-
mum data rate of 40 Mbit/s. Independent transmit and receive
functions provide greater flexibility for serial communications.
Serial port data can be automatically transferred to and from
on-chip memory via DMA. Each of the serial ports offers TDM
multichannel mode.
Addressing of external memory devices is facilitated by on-chip
decoding of high-order address lines to generate memory bank
select signals. Separate control lines are also generated for sim-
plified addressing of page-mode DRAM. The ADSP-21062
provides programmable memory wait states and external
memory acknowledge controls to allow interfacing to DRAM
and peripherals with variable access, hold and disable time
requirements.
The serial ports can operate with little-endian or big-endian
transmission formats, with word lengths selectable from 3 bits to
32 bits. They offer selectable synchronization and transmit
modes as well as optional µ-law or A-law companding. Serial
port clocks and frame syncs can be internally or externally
generated.
Host Processor Interface
The ADSP-21062’s host interface allows easy connection to
standard microprocessor buses, both 16-bit and 32-bit, with
little additional hardware required. Asynchronous transfers at
speeds up to the full clock rate of the processor are supported.
The host interface is accessed through the ADSP-21062’s exter-
nal port and is memory-mapped into the unified address space.
Four channels of DMA are available for the host interface; code
and data transfers are accomplished with low software overhead.
Multiprocessing
The ADSP-21062 offers powerful features tailored to multi-
processor DSP systems. The unified address space (see
Figure 4) allows direct interprocessor accesses of each ADSP-
21062’s internal memory. Distributed bus arbitration logic is
included on-chip for simple, glueless connection of systems
containing up to six ADSP-21062s and a host processor. Master
processor changeover incurs only one cycle of overhead. Bus
arbitration is selectable as either fixed or rotating priority. Bus lock
allows indivisible read-modify-write sequences for semaphores. A
vector interrupt is provided for interprocessor commands. Maxi-
mum throughput for interprocessor data transfer is 240 Mbytes/s
over the link ports or external port. Broadcast writes allow simulta-
neous transmission of data to all ADSP-21062s and can be used
to implement reflective semaphores.
The host processor requests the ADSP-21062’s external bus
with the host bus request (HBR), host bus grant (HBG), and
ready (REDY) signals. The host can directly read and write the
internal memory of the ADSP-21062, and can access the DMA
channel setup and mailbox registers. Vector interrupt support is
provided for efficient execution of host commands.
DMA Controller
Link Ports
The ADSP-21062’s on-chip DMA controller allows zero-
overhead data transfers without processor intervention. The
DMA controller operates independently and invisibly to the
processor core, allowing DMA operations to occur while the
core is simultaneously executing its program instructions.
The ADSP-21062 features six 4-bit link ports that provide addi-
tional I/O capabilities. The link ports can be clocked twice per
cycle, allowing each to transfer eight bits of data per cycle. Link
port I/O is especially useful for point-to-point interprocessor
communication in multiprocessing systems.
DMA transfers can occur between the ADSP-21062’s internal
memory and either external memory, external peripherals or a
host processor. DMA transfers can also occur between the
ADSP-21062’s internal memory and its serial ports or link
ports. DMA transfers between external memory and external
peripheral devices are another option. External bus packing to
16-, 32-, or 48-bit words is performed during DMA transfers.
The link ports can operate independently and simultaneously,
with a maximum data throughput of 240 Mbytes/s. Link port
data is packed into 32- or 48-bit words, and can be directly read
by the core processor or DMA-transferred to on-chip memory.
Each link port has its own double-buffered input and output
registers. Clock/acknowledge handshaking controls link port
transfers. Transfers are programmable as either transmit or
receive.
Ten channels of DMA are available on the ADSP-21062—two
via the link ports, four via the serial ports, and four via the
processor’s external port (for either host processor, other
ADSP-21062s, memory or I/O transfers). Four additional
link port DMA channels are shared with serial port 1 and the
external port. Programs can be downloaded to the ADSP-
21062 using DMA transfers. Asynchronous off-chip peripher-
als can control two DMA channels using DMA Request/
Grant lines (DMAR1-2, DMAG1-2). Other DMA features
Program Booting
The internal memory of the ADSP-21062 can be booted at
system power-up from either an 8-bit EPROM, a host proces-
sor, or through one of the link ports. Selection of the boot
source is controlled by the BMS (Boot Memory Select),
EBOOT (EPROM Boot), and LBOOT (Link/Host Boot) pins.
32-bit and 16-bit host processors can be used for booting.
REV. C
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ADI [ ADI ]
