MOTOROLA
Chapter 10. Interrupt Controller Modules
10-17
Low-Power Wakeup Operation
10.5 Low-Power Wakeup Operation
The System Control Module (SCM) contains an 8-bit low-power interrupt control register
(LPICR) used explicitly for controlling the low-power stop mode. This register must
explicitly be programmed by software to enter low-power mode.
Each interrupt controller provides a special combinatorial logic path to provide a special
wake-up signal to exit from the low-power stop mode. This special mode of operation
works as follows:
• First, LPICR[6:4] is loaded with the mask level that will be specified while the core
is in stop mode. LPICR[7] must be set to enable this mode of operation.
NOTE
The wakeup mask level taken from LPICR[6:4] is adjusted by
hardware to allow a level 7 IRQ to generate a wakeup. That is,
the wakeup mask value used by the interrupt controller must be
in the range of 0–6.
• Second, the processor executes a STOP instruction which places it in stop mode.
Once the processor is stopped, each interrupt controller enables a special logic path
which evaluates the incoming interrupt sources in a purely combinatorial path; that
is, there are no clocked storage elements. If an active interrupt request is asserted and
the resulting interrupt level is greater than the mask value contained in LPICR[6:4],
then each interrupt controller asserts the wake-up output signal, which is routed to
the SCM where it is combined with the wakeup signals from the other interrupt
controller and then to the PLL module to re-enable the device’s clock trees and
resume processing.
Summary of Contents for ColdFire MCF5281
Page 124: ...3 20 MCF5282 User s Manual MOTOROLA EMAC Instruction Set Summary ...
Page 141: ...MOTOROLA Chapter 5 Static RAM SRAM 5 5 SRAM Programming Model ...
Page 142: ...5 6 MCF5282 User s Manual MOTOROLA SRAM Programming Model ...
Page 168: ...6 26 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 186: ...7 18 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 228: ...9 22 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 246: ...10 18 MCF5282 User s Manual MOTOROLA Low Power Wakeup Operation ...
Page 254: ...11 8 MCF5282 User s Manual MOTOROLA Memory Map and Registers ...
Page 264: ...12 10 MCF5282 User s Manual MOTOROLA Chip Select Registers ...
Page 280: ...13 16 MCF5282 User s Manual MOTOROLA Misaligned Operands ...
Page 314: ...14 34 MCF5282 User s Manual MOTOROLA MCF5282 External Signals ...
Page 339: ...MOTOROLA Chapter 15 Synchronous DRAM Controller Module 15 25 SDRAM Example ...
Page 340: ...15 26 MCF5282 User s Manual MOTOROLA SDRAM Example ...
Page 356: ...16 16 MCF5282 User s Manual MOTOROLA DMA Controller Module Functional Description ...
Page 408: ...17 52 MCF5282 User s Manual MOTOROLA Buffer Descriptors ...
Page 446: ...20 24 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 474: ...22 18 MCF5282 User s Manual MOTOROLA Programming Model ...
Page 510: ...23 36 MCF5282 User s Manual MOTOROLA Operation ...
Page 526: ...24 16 MCF5282 User s Manual MOTOROLA I2C Programming Examples ...
Page 672: ...28 12 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 718: ...29 46 MCF5282 User s Manual MOTOROLA Motorola Recommended BDM Pinout ...
Page 750: ...32 8 MCF5282 User s Manual MOTOROLA Ordering Information ...