DA9138.005
12 April, 2006
APPLICATION INFORMATION
Synchronous modem with asynchronous interface
The MAS9138 is intended for applications where an asynchronous and synchronous data source must be linked
together. A typical case appears in a data modem where the terminal interface of the modem has been specified to
be asynchronous but the modem data pump operates in a synchronous fashion.
RS232C
INTERFACE
TXD
TDI
MAS9138
TDO
TXC
RDI
RXD
RDO
RXC
PHONE LINE
MODEM CIRCUITS
Synchronous serial interface with uP interface
Another application is a synchronous serial interface for uP which uses UART as a data source. The concept is
illustrated below.
UART
M AS9138
T TL/V.28
TxD
RS-232-C
V.24
RDI
uP-INTERFACE
TDO
RxD
RxC
TxC
7 (10)
MAS [ MICRO ANALOG SYSTEMS ]
