ST486DX ST Microelectronics, ST486DX Datasheet - Page 30

• Manufacturer Part Number: ST486DX
• Description: PROGRAMMING MANUAL
• Manufacturer: ST Microelectronics

ST486DX - SMM POWER MANAGEMENT FEATURES
4.3
Suspend Mode
The SGS-Thomson CPU allows suspend mode to be entered either through software or hardware.
The software initiates suspend mode through execution of a HLT instruction if CCR2 bit 3 (HALT)
is set. After the HLT instruction is executed, the CPU enters suspend mode and asserts the suspend
acknowledge (SUSPA#) pin (if the SUSP bit in CCR2 was set to enable the SUSPA# pin).
Hardware initiates suspend mode by using two new pins on the CPU, SUSP# and SUSPA#. When
SUSP# is asserted, the CPU first completes any pending instructions and bus cycles, and then enters
suspend mode. Once in suspend mode, the SUSPA# pin is asserted by the CPU.
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