Line Powered Modem plus DAA
CMX878
a) Single byte from µC
CSN
SERIAL CLOCK
COMMAND DATA
765432 10
REPLY DATA
Address (01 Hex = Reset)
Hi-Z
b) One Address and one Data byte from µC
CSN
SERIAL CLOCK
COMMAND DATA
765432 10
Address
REPLY DATA
Hi-Z
Note:
The SERIAL CLOCK line may be high
or low at the start and end of each
transaction. See figure 15.
= Level not important
765 432 10
Data to CMX878
c) One Address and 2 Data bytes from µC
CSN
SERIAL CLOCK
COMMAND DATA
765432 10
Address
REPLY DATA
Hi-Z
765 432 10
First (msb) data
byte to CMX878
765432 10
Second (lsb) data
byte to CMX878
d) One Address byte from µC and one Reply byte from CMX878
CSN
SERIAL CLOCK
COMMAND DATA
765432 10
Address
REPLY DATA
Hi-Z
765432 10
Data from CMX78
e) One Address byte from µC and 2 Reply bytes from CMX878
CSN
SERIAL CLOCK
COMMAND DATA
765432 10
Address
REPLY DATA
Hi-Z
765432 10
First (msb) byte
from CMX878
765432 10
Second(lsb) byte
from CMX878
Figure 9 C-BUS Transactions
© 2002 Consumer Microcircuits Limited
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