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MPC8240 Integrated Processor User’s Manual
Power Management
1.5 Power Management
TheMPC8240 provides both automatic and program-controllable power reduction modes
for progressive reduction of power consumption.
The MPC8240 has independent power management functionality for both the processor
core and the peripheral logic.The MPC8240 provides hardware support for three levels of
programmable power reduction for both the processor and the peripheral logic. Doze, nap,
and sleep modes are invoked by register programming—HID0 in the case of the processor
core and configuration registers in the case of the peripheral logic block.
The processor and peripheral logic blocks are both fully static, allowing internal logic states
to be preserved during all power-saving modes. The following sections describe the
programmable power modes.
1.5.1 Programmable Processor Power Management Modes
Table 1-1 summarizes the programmable power-saving modes for the processor core.
These are very similar to those available in the MPC603e device.
1.5.2 Programmable Peripheral Logic Power Management
Modes
The following subsections describe the power management modes of the peripheral logic.
Table 1-2 summarizes the programmable power-saving modes for the peripheral logic
block.
Table 1-1. Programmable Processor Power Modes
PM Mode
Functioning Units
Activation Method
Full-Power Wake Up Method
Full power
All units active
—
—
Full power
(with DPM)
Requested logic by
demand
By instruction dispatch
—
Doze
Bus snooping
Data cache as needed
Decrementer timer
Controlled by software
(write to HID0)
External asynchronous exceptions
(assertion of SMI or int),
Decrementer exception
Hard or soft reset
Machine check exception (mcp)
Nap
Decrementer timer
Controlled by software
(write to HID0) and
qualified with QACK
from peripheral logic
External asynchronous exceptions
(assertion of SMI, or int)
Decrementer exception
Negation of QACK by peripheral logic
Hard or soft reset
Machine check exception (mcp)
Sleep
None
Controlled by software
(write to HID0) and
qualified with QACK
from peripheral logic
External asynchronous exceptions
(assertion of SMI, or int)
Negation of QACK by peripheral logic
Hard or soft reset
Machine check exception (mcp)
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...