Rainbow Electronics MAX6964 - Manual (Page 8)

MAX6964
during the high period of the clock pulse. When the
master is transmitting to the MAX6964, the device gen-
erates the acknowledge bit because the MAX6964 is
the recipient. When the MAX6964 is transmitting to the
master, the master generates the acknowledge bit
because the master is the recipient.
Slave Address
The MAX6964 has a 7-bit long slave address ( Figure 6 ).
The eighth bit following the 7-bit slave address is the
R/W bit. The R/W bit is low for a write command, high
for a read command.
The second (A5), third (A4), fourth (A3), sixth (A1), and
last (A0) bits of the MAX6964 slave address are always
1, 0, 0, 0, and 0. Slave address bits A6 and A2 are
selected by the address input AD0. AD0 can be con-
nected to GND, V+, SDA, or SCL. The MAX6964 has
four possible slave addresses ( Table 1 ), and therefore
a maximum of four MAX6964 devices can be controlled
independently from the same interface.
Message Format for Writing the MAX6964
A write to the MAX6964 comprises the transmission of
the MAX6964’s slave address with the R/W bit set to
zero, followed by at least 1 byte of information. The first
byte of information is the command byte. The command
byte determines which register of the MAX6964 is to be
written to by the next byte, if received (
Table 2 ). If a
STOP condition is detected after the command byte is
received, then the MAX6964 takes no further action
beyond storing the command byte.
Any bytes received after the command byte are data
bytes. The first data byte goes into the internal register of
the MAX6964 selected by the command byte (
Figure 8 ).
17-Output LED Driver/GPO
with Intensity Control
8 _______________________________________________________________________________________
Table 1. MAX6964 Address Map
DEVICE ADDRESS
PIN AD0
A6 A5 A4 A3 A2 A1 A0
SCL 1 1 0 0 0 0 0
SDA 1 1 0 0 1 0 0
GND 0 1 0 0 0 0 0
V+ 0 1 0 0 1 0 0
Table 2. Register Address Map
REGISTER
ADDRESS CODE
(hex)
AUTOINCREMENT
ADDRESS
Blink phase 0 outputs O7–O0 0x02 0x03
Blink phase 0 outputs O15–O8 0x03 0x02
User RAM0 0x06 0x07
User RAM1 0x07 0x06
Blink phase 1 outputs O7–O0 0x0A 0x0B
Blink phase 1 outputs O15–O8 0x0B 0x0A
Master and global/O16 intensity 0x0E —
Configuration 0x0F —
Outputs intensity O1, O0 0x10 0x11
Outputs intensity O3, O2 0x11 0x12
Outputs intensity O5, O4 0x12 0x13
Outputs intensity O7, O6 0x13 0x14
Outputs intensity O9, O8 0x14 0x15
Outputs intensity O11, O10 0x15 0x16
Outputs intensity O13, O12 0x16 0x17
Outputs intensity O15, O14 0x17 0x10