System Configuration and Protection
MPC561/MPC563 Reference Manual, Rev. 1.2
6-2
Freescale Semiconductor
•
Periodic Interrupt Timer (
Section 6.1.9, “Periodic Interrupt Timer (PIT)
”)—The SIU provides a
timer to generate periodic interrupts for use with a real-time operating system or the application
software. The PIT provides a period from 1 µs to 4 seconds with a four-MHz crystal or 200 ns to
0.8 ms with a 20-MHz crystal. The PIT function can be disabled.
•
Software Watchdog Timer (
Section 6.1.10, “Software Watchdog Timer (SWT)
”)—The SWT
asserts a reset or non-maskable interrupt, as selected by the system protection control register
(SYPCR), if the software fails to service the SWT for a designated period of time (e.g., because the
software is trapped in a loop or lost). After a system reset, this function is enabled with a maximum
time-out period and asserts a system reset if the time-out is reached. The SWT can be disabled or
its time-out period can be changed in the SYPCR. Once the SYPCR is written, it cannot be written
again until a system reset.
•
Freeze Support (
Section 6.1.11, “Freeze Operation
”)—The SIU allows control of whether the
SWT, PIT, TB, DEC, and RTC should continue to run during freeze mode.
•
Low Power Stop (
Section 6.1.12, “Low Power Stop Operation
”)—In low power modes, specific
timers are frozen but others are not.
shows a block diagram of the system configuration and protection logic.
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...