Table 2-11 Host Interface - Motorola DSP56309 User Manual

Signal/Connection Descriptions
Host Interface (HI08)
Signal
Name
H0ÐH7 Input/
Output
HAD0Ð Input/
HAD7 Output
Input or
PB0ÐPB7 Output
HA0
HAS/HAS
PB8 Input or
Output
2-18

Table 2-11 Host Interface

State
Type During
Reset
Tri-stated
Input Input
Input
DSP56309UM/D
Signal Description
Host DataÑWhen the HI08 is programmed
to interface a non-multiplexed host bus and
the HI function is selected, these signals are
lines 0Ð7 of the data bidirectional, tri-state
bus.
Host AddressÑWhen HI08 is programmed
to interface a multiplexed host bus and the
HI function is selected, these signals are lines
0Ð7 of the address/data bidirectional,
multiplexed, tri-state bus.
Port B 0Ð7ÑWhen the HI08 is configured as
GPIO through the HPCR, these signals are
individually programmed as inputs or
outputs through the HI08 data direction
register (HDDR).
Host Address Input 0ÑWhen the HI08 is
programmed to interface a non-multiplexed
host bus and the HI function is selected, this
signal is line 0 of the host address input bus.
Host Address StrobeÑWhen HI08 is
programmed to interface a multiplexed host
bus and the HI function is selected, this
signal is the host address strobe (HAS)
Schmitt-trigger input. The polarity of the
address strobe is programmable but is
configured active-low (HAS) following reset.
Port B 8ÑWhen the HI08 is configured as
GPIO through the HPCR, this signal is
individually programmed as an input or
output through the HDDR.
MOTOROLA