Interrupt and Mode Control
Signals/Connections
2
-9
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 2-9. Interrupt and Mode Control
Signal Name
Type
State During
Reset
Signal Description
RESET
Input
Input
Reset—Deassertion of RESET is internally synchronized to the clock
out (CLKOUT). 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. If RESET is deasserted synchronous to CLKOUT, exact
start-up timing is guaranteed, allowing multiple processors to start and
operate synchronously. 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 after
power-up.
RESET can tolerate 5 V.
MODA/IRQA
Input
Input
Mode Select A/External Interrupt Request A—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/IRQA MODA, MODB, MODC,
and MODD select one of sixteen initial chip operating modes, latched
into the OMR when the RESET signal is deasserted.
Internally synchronized to CLKOUT. If IRQA is asserted synchronous
to CLKOUT, multiple processors can be re-synchronized using the
WAIT instruction and asserting IRQA to exit the Wait state. If a STOP
instruction puts the processor is in the Stop standby state and IRQA is
asserted, the processor exits the Stop state.
MODA/IRQA can tolerate 5 V.
MODB/IRQB
Input
Input
Mode Select B/External Interrupt Request B—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 sixteen initial chip operating modes, latched into OMR
when the RESET signal is deasserted.
Internally synchronized to CLKOUT. If IRQB is asserted synchronous
to CLKOUT, multiple processors can be re-synchronized using the
WAIT instruction and asserting IRQB to exit the Wait state.
MODB/IRQB can tolerate 5 V.
Summary of Contents for DSP56303
Page 1: ...DSP56303 User s Manual 24 Bit Digital Signal Processor DSP56303UM AD Revision 1 January 2001 ...
Page 52: ...JTAG OnCE Interface 2 22 DSP56303 User s Manual ...
Page 114: ...General Purpose Input Output GPIO 5 10 DSP56303 User s Manual ...
Page 212: ...GPIO Signals and Registers 8 26 DSP56303 User s Manual ...
Page 268: ...Interrupt Equates A 22 DSP56303 User s Manual ...
Page 306: ...Programming Sheets B 38 DSP56303 User s Manual ...
Page 320: ...Index 14 DSP56303 User s Manual ...