AMD-K6-IIIE+550ACR AMD (ADVANCED MICRO DEVICES), AMD-K6-IIIE+550ACR Datasheet - Page 172

• Manufacturer Part Number: AMD-K6-IIIE+550ACR
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AMD-K6-IIIE+550ACR

• Lead Free Status / RoHS Status: Not Compliant

AMD-K6™-IIIE+ Embedded Processor Data Sheet
6.2
Effective Bus
Frequency Divisor
(EBF[2:0])
150
Dynamic Core Frequency and Core Voltage Control
AMD PowerNow! technology-enabled processors support the
ability to change the bus frequency divisor and core voltage
transparently to the user during run-time. These features are
implemented in conjunction with a new clock control state—
For AMD PowerNow! technology state transitions, the EPMR
register is accessed using an SMM handler.
See “Clock Control” on page 277 for more information about
the EPM Stop Grant State.
The processor core frequency is controlled by the Effective Bus
Frequency Divisor—EBF[2:0]—which dictates the processor-to-
bus clock ratio supplied to the processor’s internal PLL. This
processor-to-bus clock ratio is multiplied by the external bus
frequency to set the frequency of operation for the processor
core.
Table 28 on page 149 lists valid EBF[2:0] states and equivalent
processor-to-bus clock ratios.
the EPM Stop Grant state.
The SMM handler initiates core voltage and frequency
transitions by writing a non-zero value to the Stop Grant
Time-Out Counter (SGTC) field.
This action automatically places the processor into the EPM
Stop Grant State and transitions the CPU core voltage and
frequency to the values specified in the Voltage ID Output
(VIDO) and Internal BF Divisor (IBF) fields of the BVC field.
Once the timer of the SGTC has expired, the EPM Stop
Grant State is exited and the AMD PowerNow! technology
state transition is completed.
At the fall of RESET, the EBF[2:0] value is determined by
the state of the processor BF[2:0] input pins.
Afterwards, the EBF[2:0] value can be dynamically
controlled through AMD PowerNow! technology state
transitions.
AMD PowerNow!™ Technology
Preliminary Information
23543A/0—September 2000
Chapter 6