Datasheet

MAX8660/MAX8660A/MAX8660B/MAX8661
High-Efficiency, Low-I
Q
, PMICs with Dynamic
Voltage Management for Mobile Applications
36
I
2
C Write Operation
The MAX8660/MAX8661 are write-only devices and
recognize the “write byte” protocol as defined in the
SMBus specification and shown in section A of Figure
11. The “write byte” protocol allows the I
2
C master
device to send 1 byte of data to the slave device. The
“write byte” protocol requires a register pointer address
for the subsequent write. The MAX8660/MAX8661
acknowledge any register pointer even though only a
subset of those registers actually exists in the device.
The “write byte” protocol is as follows:
1) The master sends a start command.
2) The master sends the 7-bit slave address followed
by a write bit.
3) The addressed slave asserts an acknowledge by
pulling SDA low.
4) The master sends an 8-bit register pointer.
5) The slave acknowledges the register pointer.
6) The master sends a data byte.
7) The slave updates with the new data.
8) The slave acknowledges the data byte.
9) The master sends a STOP condition.
In addition to the write-byte protocol, the MAX8660/
MAX8661 recognize the multiple byte register-data pair
protocol as shown in section B of Figure 11. This proto-
col allows the I
2
C master device to address the slave
only once and then send data to multiple registers in a
random order. Registers may be written continuously
until the master issues a STOP condition.
The multiple-byte register-data pair protocol is as
follows:
1) The master sends a start command.
2) The master sends the 7-bit slave address followed
by a write bit.
3) The addressed slave asserts an acknowledge by
pulling SDA low.
4) The master sends an 8-bit register pointer.
5) The slave acknowledges the register pointer.
6) The master sends a data byte.
7) The slave updates with the new data.
8) The slave acknowledges the data byte.
9) Steps 5 to 7 are repeated as many times as
the master requires. Registers may be accessed in
random order.
10)The master sends a STOP condition.
REGISTER
ADDRESS
REGISTER
NAME
BIT NAME FUNCTION
7MVS
V5 (VCC_MVT) voltage select:
0—Ramp V5 to voltage selected by MDTV1 (default)
1—Ramp V5 to voltage selected by MDTV2
6 MGO
Start V5 (VCC_MVT) voltage change:
0—Hold V5 at current level (default)
1—Ramp V5 as selected by MVS
5 SVS
V4 (VCC_SRAM) voltage select:
0—Ramp V4 to voltage selected by SDTV1 (default)
1—Ramp V4 to voltage selected by SDTV2
4 SGO
Start V4 (VCC_SRAM) voltage change:
0—Hold V4 at current level (default)
1—Ramp V4 as selected by SVS
3 R Reserved
2 R Reserved
1 AVS
V3 (VCC_APPS) voltage select:
0—Ramp V3 to voltage selected by ADTV1 (default)
1—Ramp V3 to voltage selected by ADTV2
0x20 VCC1
0 AGO
Start V3 (VCC_APPS) voltage change:
0—Hold V3 at current level (default)
1—Ramp V3 as selected by AVS
Table 10. DVM Voltage-Change Register (VCC1, 0x20)