Motorola DSP56301 - Manual (Page 40)

Host Interface (HI32)
2 -10 DSP56301 User’s Manual
2.7 Host Interface (HI32)
The Host Interface (HI32) provides a fast parallel data port up to 32 bits wide that can connect
directly to the host bus. The HI32 supports a variety of standard buses and provides glueless
connection with the PCI bus standard and with a number of industry-standard
microcomputers, microprocessors, DSPs and DMA hardware. The functions of the signals
associated with the HI32 vary according to the programmed configuration of the interface as
determined by the 24-bit DSP Control Register (DCTR). Refer to Chapter 6, Host Interface
(HI32) for detailed descriptions of this and other HI32 configuration registers.
Note: All HI32 inputs are 5 V tolerant.
Table 2-10. Host Interface
Signal Name Type
State During
Reset
Signal Description
HAD[0–7]
HA[3–10]
PB[0–7]
Input/Output
Input
Input or
Output
Tri-stated Host Address/Data 0–7—When the HI32 is programmed to
interface with a PCI bus and the HI function is selected, these
signals are lines 0–7 of the bidirectional, multiplexed Address/Data
bus.
Host Address 3–10—When HI32 is programmed to interface with a
universal non-PCI bus and the HI function is selected, these signals
are lines 3–10 of the input Address bus.
Port B 0–7—When the HI32 is configured as GPIO through the
DCTR, these signals are individually programmed as inputs or
outputs through the HI32 Data Direction Register (DIRH).
HAD[15–8]
HD[7–0]
PB[15–8]
Input/Output
Input/Output
Input or
Output
Tri-stated Host Address/Data 8–15—When the HI32 is programmed to
interface with a PCI bus and the HI function is selected, these
signals are lines15–8 of the bidirectional, multiplexed Address/Data
bus.
Host Data 0–7—When the HI32 is programmed to interface with a
universal non-PCI bus and the HI function is selected, these signals
are lines 7–0 of the bidirectional Data bus.
Port B 8–15—When the HI32 is configured as GPIO through the
DCTR, these signals are individually programmed as inputs or
outputs through the HI32 DIRH.