2004 Mar 16
141
Philips Semiconductors
Product specification
PC-CODEC
SAA7108E; SAA7109E
18.2
Digital video decoder part
18.2.1
I
2
C-
BUS FORMAT
ACK-s
ACK-s
DATA
SLAVE ADDRESS W
data transferred
(n bytes + acknowledge)
MHB339
P
S
ACK-s
SUBADDRESS
ACK-s
ACK-m
SLAVE ADDRESS R
MHB340
P
Sr
ACK-s
ACK-s
DATA
SUBADDRESS
SLAVE ADDRESS W
S
data transferred
(n bytes + acknowledge)
Fig.56 I
2
C-bus format.
a. Write procedure.
b. Read procedure (combined).
Table 146
Description of I
2
C-bus format; note 1
Notes
1.
2.
The SAA7108E; SAA7109E supports the ‘fast mode’ I
2
C-bus specification extension (data rate up to 400 kbits/s).
If pin RTCO strapped to V
DDD
via a 3.3 k
resistor.
CODE
DESCRIPTION
S
Sr
SLAVE ADDRESS W
SLAVE ADDRESS R
ACK-s
ACK-m
SUBADDRESS
DATA
START condition
repeated START condition
‘0100 0010’ (42H, default) or ‘0100 0000’ (40H; note 2)
‘0100 0011’ (43H, default) or ‘0100 0001’ (41H; note 2)
acknowledge generated by the slave
acknowledge generated by the master
subaddress byte; see Tables 147 and 148
data byte; see Table 148; if more than one byte DATA is transmitted the subaddress pointer is
automatically incremented
STOP condition
read/write control bit (LSB slave address); X = 0, order to write (the circuit is slave receiver);
X = 1, order to read (the circuit is slave transmitter)
P
X