Clocks and Power Control
MPC561/MPC563 Reference Manual, Rev. 1.2
8-18
Freescale Semiconductor
The return to normal-high mode from normal-low, doze-high, low, and sleep mode is accomplished with
the asynchronous interrupt. The sources of the asynchronous interrupt are:
•
Asynchronous wake-up interrupt from the interrupt controller
•
RTC, PIT, or time base interrupts (if enabled)
•
Decrementer exception
The system responds quickly to asynchronous interrupts. The wake-up time from normal-low, doze-high,
doze-low, and sleep mode caused by an asynchronous interrupt or a decrementer exception is only three
to four clock cycles of maximum system frequency. In 40-MHz systems, this wake-up requires 75 to 100
ns. The asynchronous wake-up interrupt from the interrupt controller is level sensitive one. It will therefore
be negated only after the reset of interrupt cause in the interrupt controller.
The timers’ (RTC, PIT, time base, or decrementer) interrupts indications set status bits in the PLPRCR
(TMIST). The clock module considers this interrupt to be pending asynchronous interrupt as long as the
TMIST is set. The TMIST status bit should be cleared before entering any low-power mode.
summarizes wake-up operation for each of the low-power modes.
8.7.3.1
Exiting from Normal-Low Mode
In normal mode (as well as doze mode), if the PLPRCR[CSRC] bit is set, the system toggles between low
frequency (defined by PLPRCR[DFNL]) and high frequency (defined by PLPRCR[DFNH]. The system
switches from normal-low mode to normal-high mode if either of the following conditions is met:
•
An interrupt is pending from the interrupt controller; or
•
The MSR[POW] bit is cleared (power management is disabled).
When neither of these conditions are met, the PLPRCR[CSRC] bit is set, and the asynchronous interrupt
status bits are reset, the system returns to normal-low mode.
Table 8-6. Power Mode Wake-Up Operation
Operation Mode
Wake-up
Method
Return Time from Wake-up
Event to Normal-High
Normal-low (“gear”)
Software
or
Interrupt
Asynchronous interrupts:
3-4 maximum system cycles
Synchronous interrupts:
3-4 actual system cycles
Doze-high
Interrupt
Doze-low
Interrupt
Sleep
Interrupt
3-4 maximum system clocks
Deep-sleep
Interrupt
< 500 Oscillator Cycles
125 µs – 4 MHz
25 µs – 20 MHz
Power-down
Interrupt <
500
oscillator power
supply wake-up
IRAMSTBY
External
Power-on sequence
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...