Introduction; Hi08 Features - Motorola DSP56309 User Manual

6.1

INTRODUCTION

The Host Interface (HI08) is a byte-wide, full-duplex, double-buffered parallel port that
can connect directly to the data bus of a host processor. The HI08 supports a variety of
buses and provides glueless connection with a number of industry-standard
microcomputers, microprocessors, and DSPs.
The host bus can operate asynchronously to the DSP core clock, so the HI08 registers are
divided into two banks. The host register bank is accessible to the external host and the
DSP register bank is accessible to the DSP core.
The HI08 supports two classes of interfaces:
¥ Host Processor/Microcontroller (MCU) connection interface
¥ GPIO port
Signals not used as HI08 port signals can be configured as GPIO signals, up to a total of
16.
6.2

HI08 FEATURES

This section lists the features of the host-to-DSP and DSP-to-host interfaces. Further
details are given in Section 6.5ÑHI08 DSP Side ProgrammerÕs Model and
Section 6.8ÑHI08 Programming Model Quick Reference. Also, see Table 6-13 on
page 6-34.
6.2.1 Host to DSP Core Interface
¥ Mapping:
Ð Registers are directly mapped into eight internal X data memory locations
¥ Data word:
Ð DSP56309 24-bit (native) data words are supported, as are 8-bit and 16-bit
words
¥ Transfer modes:
Ð DSP-to-host
Ð Host-to-DSP
MOTOROLA DSP56309UM/D
Host Interface (HI08)
Introduction
6-3