Z85233 Datasheet, PDF (73/317 Pages) Zilog, Inc. – The Zilog SCC Serial Communication Controller

SCC™/ESCC™ User’s Manual
SCC/ESCC Ancillary Support Circuitry
3.5 CLOCK SELECTION (Continued)
2. The x1 mode in Asynchronous mode is a combination
of both synchronous and asynchronous transmission.
The data is clocked by a common timing base, but
characters are still framed with Start and Stop bits.
Because the receiver waits for one clock period after
/SYNC
/RTxC
OSC
OSC
/TRxC
detecting the first High-to-Low transition before
beginning to assemble characters, the data and clock
is synchronized externally. The x1 mode is the only
mode in which a data encoding method other than
NRZ is used.
RX
Receiver
TX
Transmitter
Baud Rate
Generator Out
Tx DPLL Out
Rx DPLL Out
PCLK
Echo
Echo
DPLL
BRG
Figure 3-10. Clock Multiplexer
DPLL
Baud Rate
Generator
3-12
UM010901-0601