ISL62773 Datasheet, PDF (25/37 Pages) Intersil Corporation – Multiphase PWM Regulator for AMD Fusion™ Desktop CPUs Using SVI 2.0

ISL62773
SVC
SVD
VID bits [7:1]
VID
bit [0]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
ACK
ACK
ACK
FIGURE 19. SVD PACKET STRUCTURE
SVI Bus Protocol
The AMD processor bus protocol is compliant with SMBus send
byte protocol for VID transactions. The AMD SVD packet structure
is shown in Figure 19. The description of what each bit of the
three bytes that make up the SVI command are shown in Table 8.
During a transaction, the processor sends the start sequence
followed by each of the three bytes, which end with an optional
acknowledge bit. The ISL62773 does not drive the SVD line
during the ACK bit. Finally, the processor sends the stop
sequence. After the ISL62773 has detected the stop, it can then
proceed with the commanded action from the transaction.
TABLE 8. SVD DATA PACKET
BITS
DESCRIPTION
1:5 Always 11000b
6 Core domain selector bit, if set then the following data byte
contains VID, power state, telemetry control, load line trim and
offset trim apply to the Core VRwer4444.
7 Northbridge domain selector bit, if set then the following data
byte contains VID, power state, telemetry control, load line trim
and offset trim apply to the Northbridge VR.
8 Always 0b
9 Acknowledge Bit
10 PSI0_L
11:17 VID Code bits [7:1]
18 Acknowledge Bit
19 VID Code bit [0]
20 PSI1_L
21 TFN (Telemetry Functionality)
22:24 Load Line Slope Trim
25:26 Offset Trim [1:0]
27 Acknowledge Bit
Power States and Telemetry
SVI2 defines two power state indicator levels, see Table 9. As
processor current consumption is reduces the power state
indicator level increases starting with 0.
For the Core VR operating in 3-phase mode, when PSI0_L is
asserted Channel 3 is tri-stated to boost efficiency. When PSI1_L
is asserted, Channel 2 is tri-stated and Channel 1 enters diode
emulation mode to further boost efficiency. In 2-phase mode,
when PSI0_L is asserted, Channel 2 is tri-stated. Asserting
PSI1_L in this mode results in Channel 1 entering diode
emulation mode.
For the Northbridge VR operating in 2-phase mode, when PSI0_L
is asserted Channel 2 is tri-stated to boost efficiency. When
PSI1_L is asserted Channel 1 enters diode emulation mode to
further boost efficiency.
It is possible for the processor to assert or deassert PSI0_L and
PSI1_L out of order. PSI0_L takes priority over PSI1_L. If PSI0_L
is deasserted while PSI1_L is still asserted, the ISL62773 will
return the selected VR back full channel CCM operation.
TABLE 9. PSI0_L, PSI1_L AND TFN DEFINITION
FUNCTION Bit
DESCRIPTION
PSI0_L
10 Power State Indicate level 0. When this signal is
asserted (active Low) the processor is in a low
enough power state for the ISL62773 to take action
to boost efficiency by dropping phases.
PSI1_L
20 Power State Indicate level 1. When this signal is
asserted (active Low) the processor is in a low
enough power state for the ISL62773 to take
additional action to boost efficiency beyond that
taken with PSI0_L asserted.
TFN
21 Telemetry Functionality. This is an active high signal
that allows the processor to control the telemetry
functionality of the VR.
The TFN bit along with the Core and Northbridge domain selector
bits are used by the processor to change the functionality of
telemetry, see Table 10 for more information.
TABLE 10. TFN TRUTH TABLE
TFN, Core, NB
bits [21,6,7]
DESCRIPTION
1,0,1
Telemetry is in voltage and current mode. Therefore,
voltage and current are sent for VDD and VDDNB
domains by the controller.
1,0,0
Telemetry is in voltage mode only. Only the voltage of
VDD and VDDNB domains is sent by the controller.
1,1,0
Telemetry is disabled.
1,1,1
Reserved
25
March 7, 2012
FN8263.0