MC9S08QE128 MCU Series Reference Manual, Rev. 2
Freescale Semiconductor
89
Chapter 5
Resets, Interrupts, and General System Control
5.1
Introduction
This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupt
in the MC9S08QE128 Series. Some interrupt sources from peripheral modules are discussed in greater
detail within other sections of this reference manual. This section gathers basic information about all reset
and interrupt sources in one place for easy reference. A few reset and interrupt sources, including the
computer operating properly (COP) watchdog are not part of on-chip peripheral systems with their own
chapters.
5.2
Features
Reset and interrupt features include:
•
Multiple sources of reset for flexible system configuration and reliable operation
•
Reset status register (SRS) to indicate source of most recent reset
•
Separate interrupt vector for most modules (reduces polling overhead) (see
)
5.3
MCU Reset
Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset,
most control and status registers are forced to initial values and the program counter is loaded from the
reset vector (0xFFFE:0xFFFF). On-chip peripheral modules are disabled and I/O pins are initially
configured as general-purpose high-impedance inputs with pull-up devices disabled. The I bit in the
condition code register (CCR) is set to block maskable interrupts so the user program has a chance to
initialize the stack pointer (SP) and system control settings. SP is forced to 0x00FF at reset.
The MC9S08QE128 Series has the following sources for reset:
•
Power-on reset (POR)
•
External pin reset (PIN)
•
Computer operating properly (COP) timer
•
Illegal opcode detect (ILOP)
•
Low-voltage detect (LVD)
•
Background debug forced reset
Each of these sources, with the exception of the background debug forced reset, has an associated bit in
the system reset status register (SRS).
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Страница 49: ...Chapter 3 Modes of Operation MC9S08QE128 MCU Series Reference Manual Rev 2 50 Freescale Semiconductor ...
Страница 138: ...Chapter 6 Parallel Input Output Control MC9S08QE128 MCU Series Reference Manual Rev 2 138 Freescale Semiconductor ...
Страница 144: ...Chapter 7 Keyboard Interrupt S08KBIV2 MC9S08QE128 MCU Series Reference Manual Rev 2 144 Freescale Semiconductor ...
Страница 166: ...Chapter 8 Central Processor Unit S08CPUV4 MC9S08QE128 MCU Series Reference Manual Rev 2 166 Freescale Semiconductor ...
Страница 174: ...MC9S08QE128 MCU Series Reference Manual Rev 2 174 Freescale Semiconductor Analog Comparator S08ACMPV3 ...
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Страница 282: ...Serial Peripheral Interface S08SPIV3 MC9S08QE128 MCU Series Reference Manual Rev 2 282 Freescale Semiconductor ...
Страница 306: ...Timer PWM Module S08TPMV3 MC9S08QE128 MCU Series Reference Manual Rev 2 306 Freescale Semiconductor ...
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