Rainbow Electronics MAX8982X - Manual (Page 43)

Power-Management ICs for
ICERA E400/E450 Platform
MAX8982A/MAX8982X
43
4) The master sends the 8-bit register pointer of the first
register to write.
5) The slave acknowledges the register pointer.
6) The master sends a data byte.
7) The slave acknowledges the data byte.
8) The slave updates with the new data.
9) Steps 6 to 8 are repeated for as many registers in
the block, with the register pointer automatically
incremented each time.
10) The master sends a STOP condition.
Read Operations
Use the following method to read a sequential block of
registers (Figure 18):
1) The master sends a start command.
2) The master sends the 7-bit slave address followed
by a write bit (0x83).
3) The addressed slave asserts an acknowledge by
pulling SDA low.
4) The master sends an 8-bit register pointer of the first
register in the block.
5) The slave acknowledges the register pointer.
6) The master sends a repeated START condition.
7) The master sends the 7-bit slave address followed
by a read bit.
8) The slave asserts an acknowledge by pulling SDA low.
9) The slave sends the 8-bit data (contents of the register).
10) The master asserts an acknowledge by pulling
SDA low when there is more data to read, or a not
acknowledge by keeping SDA high when all data
has been read.
11) Steps 9 and 10 are repeated for as many registers
in the block, with the register pointer automatically
incremented each time.
12) The master sends a STOP condition.
The register pointer can be omitted from the above pro-
cedure when starting from register 0x00.
Figure 18. Reading from the ICs
1
S
NUMBER OF BITS
R/W
SLAVE ADDRESS
7
0
1 8
REGISTER POINTER
1 1 1 7
SLAVE ADDRESS
1 1
SLAVE TO
MASTER
MASTER TO
SLAVE
LEGEND
a) READING A SINGLE REGISTER
1
S
NUMBER OF BITS
R/W
SLAVE ADDRESS
7
0
1 8
REGISTER POINTER X
1
A
1 1 7
SLAVE ADDRESS
1
b) READING MULTIPLE REGISTERS
...
8
DATA X+1
1 8
DATA X+n-1
1 NUMBER OF BITS
...
8
DATA X
1
R/W
A A
A A A
A Sr A 1
8
DATA
1
P
1
A A
1
1 Sr
...
8
DATA X+n
1 1
A P
R/W