Parallel Host Interface (Hdi08) - Motorola DSP56367 User Manual

Table 2-8 Interrupt and Mode Control (Continued)
Signal Name Type
MODC/IRQC Input
MODD/IRQD Input
RESET Input
2.7

PARALLEL HOST INTERFACE (HDI08)

The HDI08 provides a fast, 8-bit, parallel data port that may be connected directly to the host
bus. The HDI08 supports a variety of standard buses and can be directly connected to a
number of industry standard microcomputers, microprocessors, DSPs, and DMA hardware.
MOTOROLA
State
during
Reset
Input Mode Select C/External Interrupt Request C—MODC/IRQC is an active-low
Schmitt-trigger input, internally synchronized to the DSP clock. MODC/IRQC selects the
initial chip operating mode during hardware reset and becomes a level-sensitive or
negative-edge-triggered, maskable interrupt request input during normal instruction
processing. MODA, MODB, MODC, and MODD select one of 16 initial chip operating
modes, latched into OMR when the RESET signal is deasserted.
This input is 3.3V tolerant.
Input Mode Select D/External Interrupt Request D—MODD/IRQD is an active-low
Schmitt-trigger input, internally synchronized to the DSP clock. MODD/IRQD selects the
initial chip operating mode during hardware reset and becomes a level-sensitive or
negative-edge-triggered, maskable interrupt request input during normal instruction
processing. MODA, MODB, MODC, and MODD select one of 16 initial chip operating
modes, latched into OMR when the RESET signal is deasserted.
This input is 3.3V tolerant.
Input Reset—RESET is an active-low, Schmitt-trigger input. When asserted, the chip is placed in
the Reset state and the internal phase generator is reset. The Schmitt-trigger input allows a
slowly rising input (such as a capacitor charging) to reset the chip reliably. When the
RESET signal is deasserted, the initial chip operating mode is latched from the MODA,
MODB, MODC, and MODD inputs. The RESET signal must be asserted during power up.
A stable EXTAL signal must be supplied while RESET is being asserted.
This input is 3.3V tolerant.
DSP56367
Signal/Connection Descriptions
Parallel Host Interface (HDI08)
Signal Description
2-9