Motorola DSP56301 - Manual (Page 28)

Peripherals
1 -12 DSP56301 User’s Manual
1.7 Peripherals
In addition to the core features, the DSP56301 provides the following peripherals:
n As many as 42 user-configurable General-Purpose Input/Output (GPIO) signals
n Host Interface (HI32)
n Dual Enhanced Synchronous Serial Interfaces (ESSI0 and ESSI1)
n Serial Communications Interface (SCI)
n Triple timer module
1.7.1 General-Purpose Input/Output (GPIO) signals
The GPIO port consists of as many as 42 programmable signals, all of which are also used by
the peripherals (HI32, ESSI, SCI, and timer). There are no dedicated GPIO signals. After a
reset, the signals are automatically configured as GPIO. Three memory-mapped registers per
peripheral control GPIO functionality. Programming techniques for these registers to control
GPIO functionality are detailed in Chapter 5,
Programming the Peripherals.
1.7.2 Host Interface (HI32)
The Host Interface (HI32) is a fast parallel host port up to 32 bits wide that can directly
connect to the host bus. The HI32 supports a variety of standard buses and provides glueless
connection with a number of industry-standard microcomputers, microprocessors, DSPs, and
DMA controllers. In one of its modes of operation, PCI mode, the HI32 is a dedicated
bidirectional target (slave) / initiator (master) parallel port with a 32-bit wide data path up to
eight words deep. The HI32 can connect directly to the PCI bus.
1.7.3 Enhance Synchronous Serial Interface (ESSI)
The DSP56301 provides two independent and identical ESSIs. Each ESSI has a full-duplex
serial port for communication with a variety of serial devices, including one or more
industry-standard CODECs, other DSPs, microprocessors, and peripherals that implement the
Motorola Serial Peripheral Interface (SPI). The ESSI consists of independent transmitter and
receiver sections and a common ESSI clock generator. ESSI capabilities include:
n Independent (asynchronous) or shared (synchronous) transmit and receive sections
with separate or shared internal/external clocks and frame syncs
n Normal mode operation using frame sync
n Network mode operation with as many as 32 time slots
n Programmable word length (8, 12, 16, 24, or 32 bits)
n Program options for frame synchronization and clock generation
n One receiver and three transmitters per ESSI