Datasheet

ing a write (Figure 8). The master can now read n con-
secutive bytes from the MAX6956, with the first data
byte being read from the register addressed by the ini-
tialized command byte. When performing read-after-
write verification, remember to reset the command
byte’s address because the stored control byte
address generally has been autoincremented after the
write (Table 4). Table 5 is the register address map.
Operation with Multiple Masters
If the MAX6956 is operated on a 2-wire interface with
multiple masters, a master reading the MAX6956
should use a repeated start between the write, which
sets the MAX6956’s address pointer, and the read(s)
that takes the data from the location(s). This is because
it is possible for master 2 to take over the bus after
master 1 has set up the MAX6956’s address pointer but
before master 1 has read the data. If master 2 subse-
MAX6956
2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or
28-Port LED Display Driver and I/O Expander
______________________________________________________________________________________ 11
COMMAND BYTE ADDRESS RANGE AUTOINCREMENT BEHAVIOR
x0000000 to x1111110 Command address autoincrements after byte read or written
x1111111 Command address remains at x1111111 after byte written or read
PIN
CONNECTION
DEVICE ADDRESS
AD1 AD0 A6 A5 A4 A3 A2 A1 A0
GND GND 1 0 0 0 0 0 0
GND V+ 1000001
GND SDA 1000010
GND SCL 1000011
V+ GND 1000100
V+ V+ 1000101
V+ SDA 1000110
V+ SCL 1000111
SDA GND 1001000
SDA V+ 1001001
SDA SDA 1 0 0 1 0 1 0
SDA SCL 1 0 0 1 0 1 1
SCL GND 1001100
SCL V+ 1001101
SCL SDA 1 0 0 1 1 1 0
SCL SCL 1 0 0 1 1 1 1
SA A AP0
SLAVE ADDRESS
COMMAND BYTE
DATA BYTE
ACKNOWLEDGE FROM MAX6956
D15 D14 D13 D12 D11 D10 D9 D8 D1 D0D3 D2D5 D4D7 D6
HOW COMMAND BYTE AND DATA BYTE MAP INTO MAX6956's REGISTER
ACKNOWLEDGE FROM MAX6956
R/W
n BYTES
AUTOINCREMENT MEMORY WORD ADDRESS
ACKNOWLEDGE FROM MAX6956
Figure 10. n Data Bytes Received
Table 3. MAX6956 Address Map
Table 4. Autoincrement Rules