Motorola DSP56303 User Manual page 43

Signal Name Type
HDS/HDS Input
HWR/HWR Input
PB12 Input or
Output
HCS Input
HA10 Input
PB13 Input or
Output
HREQ/HREQ Output
HTRQ/HTRQ Output
PB14 Input or
Output
Table 2-11. Host Interface (Continued)
State During
1
Reset or Stop
Disconnected Host Data Strobe—When the HI08 is programmed to interface with a
internally single-data-strobe host bus and the HI function is selected, this signal is
the Host Data Strobe (HDS) Schmitt-trigger input. The polarity of the
data strobe is programmable, but is configured as active-low (HDS)
following reset.
Host Write Data—When the HI08 is programmed to interface with a
double-data-strobe host bus and the HI function is selected, this signal
is the Host Write Data Strobe (HWR) Schmitt-trigger input. The polarity
of the data strobe is programmable, but is configured as active-low
(HWR) following reset.
Port B 12—When the HI08 is configured as GPIO through the HPCR,
this signal is individually programmed through the HDDR.
This input is 5 V tolerant.
Disconnected Host Chip Select—When the HI08 is programmed to interface with a
internally non-multiplexed host bus and the HI function is selected, this signal is
the Host Chip Select (HCS) input. The polarity of the chip select is
programmable, but is configured active-low (HCS) after reset.
Host Address 10—When the HI08 is programmed to interface with a
multiplexed host bus and the HI function is selected, this signal is line
10 of the Host Address bus.
Port B 13—When the HI08 is configured as GPIO through the HPCR,
this signal is individually programmed through the HDDR.
This input is 5 V tolerant.
Disconnected Host Request—When the HI08 is programmed to interface with a
internally single host request host bus and the HI function is selected, this signal
is the Host Request (HREQ) output. The polarity of the host request is
programmable, but is configured as active-low (HREQ) following reset.
The host request can be programmed as a driven or open-drain output.
Transmit Host Request—When the HI08 is programmed to interface
with a double host request host bus and the HI function is selected, this
signal is the Transmit Host Request (HTRQ) output. The polarity of the
host request is programmable, but is configured as active-low (HTRQ)
following reset. The host request may be programmed as a driven or
open-drain output.
Port B 14—When the HI08 is programmed to interface with a
multiplexed host bus and the signal is configured as GPIO through the
HPCR, this signal is individually programmed through the HDDR.
This input is 5 V tolerant.
Signals/Connections
Host Interface (HI08)
Signal Description
2-13