Motorola DSP56301 - Manual (Page 41)

Host Interface (HI32)
Signals/Connections 2 -11
HC0–HC3/
HBE[3–0]
HA[2–0]
PB[19–16]
Input/Output
Input
Input or
Output
Tri-stated Command 0–3/Byte Enable 0–3—When the HI32 is programmed
to interface with a PCI bus and the HI function is selected, these
signals are lines7–0 of the bidirectional, multiplexed Address/Data
bus.
Host Address 0–2—When the HI32 is programmed to interface
with a universal non-PCI bus and the HI function is selected, these
signals are lines 2–0 of the input Address bus.
The fourth signal in this set should be connected to a pull-up resistor
or directly to V
CC
when a non-PCI bus is used.
Port B 16–19—When the HI32 is configured as GPIO through the
DCTR, these signals are individually programmed as inputs or
outputs through the HI32 DIRH.
HTRDY
HDBEN
PB20
Input/
Output
Output
Input or
Output
Tri-stated Host Target Ready—When the HI32 is programmed to interface
with a PCI bus and the HI function is selected, this is the Host
Target Ready signal.
Host Data Bus Enable—When HI32 is programmed to interface
with a universal non-PCI bus and the HI function is selected, this
signal is Host Data Bus Enable output.
Port B 20—When the HI32 is configured as GPIO through the
DCTR, this signal is individually programmed as an input or output
through the HI32 DIRH.
HIRDY
HDBDR
PB21
Input/
Output
Output
Input or
Output
Tri-stated Host Initiator Ready—When the HI32 is programmed to interface
with a PCI bus and the HI function is selected, this is the Host
Initiator Ready signal.
Host Data Bus Direction—When HI32 is programmed to interface
with a universal non-PCI bus and the HI function is selected, this
signal is Host Data Bus Direction output.
Port B 21—When the HI32 is configured as GPIO through the
DCTR, this signal is individually programmed as an input or output
through the HI32 DIRH.
HDEVSEL
HSAK
PB22
Input/
Output
Output
Input or
Output
Tri-stated Host Device Select—When the HI32 is programmed to interface
with a PCI bus and the HI function is selected, this is the Host
Device Select signal.
Host Select Acknowledge—When HI32 is programmed to
interface with a universal non-PCI bus and the HI function is
selected, this signal is Host Select Acknowledge output.
Port B 22—When the HI32 is configured as GPIO through the
DCTR, this signal is individually programmed as an input or output
through the HI32 DIRH.
Table 2-10. Host Interface (Continued)
Signal Name Type
State During
Reset
Signal Description