ISL6324A Datasheet, PDF (26/39 Pages) Intersil Corporation – Monolithic Dual PWM Hybrid Controller Powering AMD SVI Split-Plane and PVI Uniplane Processors

ISL6324A
then sends a new control byte with the R/W bit set to 1,
indicating a read. The ISL6324A will then respond by
sending the master an Acknowledge, followed by the data
byte stored in register RGS1. The master must then send an
Acknowledge, and after doing so, the ISL6324A will respond
by sending the data byte stored in register RGS2. The
master must then send another Acknowledge, which the
ISL6324A will respond to by sending the data byte stored in
register RGS3. The master must then send a Not
Acknowledge followed by a Stop command, which will
complete the read transaction.
Resetting the Internal Registers
The ISL6324A’s internal I²C registers always initialize to the
states shown in Table 6 when the controller first receives
power. Once the voltage on the VCC pin rises above the
I²C Read and Write Protocol
WRITE TO A SINGLE REGISTER
S 1000_1100 A 0000_0000 A RGS1_DATA A P
POR rising threshold level, these registers can be changed
at any time via the I²C interface. If the voltage on the VCC
pin falls below the POR falling threshold, the internal
registers are automatically reset to their initial states.
TABLE 6. I2C REGISTER INITIAL STATES
REGISTER
ADDRESS
INITIAL STATE
RGS1
0000_0000
0000_0000
RGS2
0000_0001
0000_0000
RGS3
0000_0010
0000_0001
It is possible to reset the internal registers without powering
down the controller and without requiring the controller to
stop regulating and soft-start again. Simply write the initial
states to the internal registers over the I²C interface.
WRITE TO ALL REGISTERS
S 1000_1100 A 0000_0000 A RGS1_DATA A RGS1_DATA A RGS1_DATA A P
READ FROM SINGLE REGISTER
S 1000_1100 A REG_ADDR A P S 1000_1101 A RGS1_DATA N P
READ FROM ALL REGISTERS
S 1000_1100 A 0000_0000 A P S 1000_1101 A RGS1_DATA A RGS2_DATA A RGS3_DATA N P
DRIVEN BY MASTER
S = START CONDITION
A = ACKNOWLEDGE
DRIVEN BY ISL6324A
P = STOP CONDITION
N = NO ACKNOWLEDGE
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FN6880.1
April 29, 2010