ADBM-A350 Datasheet, PDF (23/55 Pages) AVAGO TECHNOLOGIES LIMITED – Optical Finger Navigation

Example: Multiple-Byte Read from Sensor Register using ‘ai’ bit
The ai is a useful feature, especially in the case of reading Delta_X, Delta_Y, and Delta_HI in succession once either the
DATA_RDY interrupt pin and/or update bit in the STATUS register bit are set.
Once the ai bit is set, the slave will deliver data packets from successive addresses until the ‘STOP’ condition from the
host.
In the example below, 3 bytes are read successively from registers 0x03, 0x04, and 0x05.
Packet
number
ADBS Address
0 x 57
1
Register Address
0 x 03
2
Packet
type
SDA
host
SDA
ADBS
DA
RA
7
0
START 1010111 0
R/W
7
0
1 0000011
ai
ACK
ACK
Packet
number
ADBS
Address 0 x 57
3
ADBS Data
from address
0 x 03
4
ADBS Data
from address
0 x 04
5
ADBS Data
from address
0 x 05
6
Packet
type
SDA
host
SDA
ADBS
DA
DP
DP
7
0
START 1010111 1
ACK
ACK
R/W
7
0
7
0
ACK 10101101
00000001
Figure 20. TWI ai bit
DP
10000101
Host could
also drive
another
START
NAK STOP _condition
instead of a
STOP
condition
23