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Signal/Connection Descriptions
Parallel Host Interface (HDI08)
Signal Name
Type
HCS
Input
HA10
Input
PB13
Input, output, or
disconnected
HOREQ/HOREQ
Output
HTRQ/
Output
HTRQ
PB14
Input, output, or
disconnected
HACK/
Input
HACK
HRRQ/
Output
HRRQ
PB15
Input, output, or
disconnected
2-12
Table 2-9 Host Interface (Continued)
State during
Reset
GPIO
Host Chip Select—When HDI08 is programmed to interface a
disconnected
nonmultiplexed 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 HDI08 is programmed to interface a multiplexed
host bus and the HI function is selected, this signal is line 10 of the host
address (HA10) input bus.
Port B 13—When the HDI08 is configured as GPIO, this signal is
individually programmed as input, output, or internally disconnected.
The default state after reset for this signal is GPIO disconnected.
This input is 3.3V tolerant.
GPIO
Host Request—When HDI08 is programmed to interface a single host
disconnected
request host bus and the HI function is selected, this signal is the host
request (HOREQ) output. The polarity of the host request is
programmable, but is configured as active-low (HOREQ) following reset.
The host request may be programmed as a driven or open-drain output.
Transmit Host Request—When HDI08 is programmed to interface 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 HDI08 is configured as GPIO, this signal is
individually programmed as input, output, or internally disconnected.
The default state after reset for this signal is GPIO disconnected.
This input is 3.3V tolerant.
GPIO
Host Acknowledge—When HDI08 is programmed to interface a single
disconnected
host request host bus and the HI function is selected, this signal is the host
acknowledge (HACK) Schmitt-trigger input. The polarity of the host
acknowledge is programmable, but is configured as active-low (HACK)
after reset.
Receive Host Request—When HDI08 is programmed to interface a
double host request host bus and the HI function is selected, this signal is
the receive host request (HRRQ) output. The polarity of the host request is
programmable, but is configured as active-low (HRRQ) after reset. The
host request may be programmed as a driven or open-drain output.
Port B 15—When the HDI08 is configured as GPIO, this signal is
individually programmed as input, output, or internally disconnected.
The default state after reset for this signal is GPIO disconnected.
This input is 3.3V tolerant.
DSP56367
Signal Description
MOTOROLA
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