
Interrupt and Mode Control
DSP56364 Technical Data, Rev. 4
2-6
Freescale Semiconductor
2.6
Interrupt and Mode Control
The interrupt and mode control signals select the chip’s operating mode as it comes out of hardware reset. 
After RESET is deasserted, these inputs are hardware interrupt request lines.
Table 2-8   Interrupt and Mode Control
Signal Name
Type
State during 
Reset
Signal Description
MODA/
IRQA
Input
Input
Mode Select A/External Interrupt Request A—
MODA/
IRQA
 is an active-low 
Schmitt-trigger input, internally synchronized to the internal system clock. 
MODA/
IRQA
 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, and MODD select one 
of 8 initial chip operating modes, latched into the OMR when the 
RESET
 signal 
is deasserted. If 
IRQA
 is asserted synchronous to the internal system clock, 
multiple processors can be re synchronized using the WAIT instruction and 
asserting 
IRQA
 to exit the wait state. If the processor is in the stop standby state 
and 
IRQA
 is asserted, the processor will exit the stop state. 
This input is 5 V tolerant
.
MODB/
IRQB
Input
Input
Mode Select B/External Interrupt Request B—
MODB/
IRQB
 is an active-low 
Schmitt-trigger input, internally synchronized to the internal system clock. 
MODB/
IRQB
 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, and MODD select one 
of 8 initial chip operating modes, latched into OMR when the 
RESET
 signal is 
deasserted. If 
IRQB
 is asserted synchronous to the internal system clock, 
multiple processors can be re-synchronized using the WAIT instruction and 
asserting 
IRQB
 to exit the wait state. 
This input is 5 V tolerant.
MODD/
IRQD
Input
Input
Mode Select D/External Interrupt Request D
—MODD/
IRQD
 is an active-low 
Schmitt-trigger input, internally synchronized to the internal system 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, and MODD select one 
of 8 initial chip operating modes, latched into OMR when the 
RESET
 signal is 
deasserted. If 
IRQD
 is asserted synchronous to the internal system clock, 
multiple processors can be re synchronized using the WAIT instruction and 
asserting 
IRQD
 to exit the wait state. 
This input is 5 V tolerant.
RESET
Input
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, and MODD inputs. The 
RESET
 signal must be asserted during power up. A stable EXTAL signal must 
be supplied before deassertionof 
RESET
.
This input is 5 V tolerant
.