Electrical Specifications
84
Datasheet
7
Electrical Specifications
7.1
Power and Ground Pins
The processor has V
CC
, V
TT
, V
DDQ,
V
CCPLL,
V
AXG
and V
SS
(ground) inputs for on-chip
power distribution. All power pins must be connected to their respective processor
power planes, while all V
SS
pins must be connected to the system ground plane. Use of
multiple power and ground planes is recommended to reduce I*R drop. The V
CC
pins
must be supplied with the voltage determined by the processor
V
oltage
ID
entification
(VID) signals. Likewise, the V
AXG
pins must also be supplied with the voltage
determined by the GFX_VID signals.
specifies the voltage level for the
various VIDs. The voltage levels are the same for both the processor VIDs and
GFX_VIDs.
7.2
Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the processor is
capable of generating large current swings between low- and full-power states. To keep
voltages within specification, output decoupling must be properly designed.
Caution:
Design the board to ensure that the voltage provided to the processor remains within
the specifications listed in
. Failure to do so can result in timing violations or
reduced lifetime of the processor.
7.2.1
Voltage Rail Decoupling
The voltage regulator solution must:
•
provide sufficient decoupling to compensate for large current swings generated
during different power mode transitions.
•
provide low parasitic resistance from the regulator to the socket.
•
meet voltage and current specifications as defined in
7.3
Processor Clocking (BCLK, BCLK#)
The processor utilizes a differential clock to generate the processor core(s) operating
frequency, memory controller frequency, and other internal clocks. The processor core
frequency is determined by multiplying the processor core ratio by 133 MHz. Clock
multiplying within the processor is provided by an internal phase locked loop (PLL),
which requires a constant frequency input, with exceptions for Spread Spectrum
Clocking (SSC).
The processor’s maximum core frequency is configured during power-on reset by using
its manufacturing default value. This value is the highest core multiplier at which the
processor can operate.
