Zilog Z16C35 - Manual (Page 37)

ISCC
User Manual
UM011002-0808
31
Initializing the baud rate generator is done in three steps. First, the time-constant is deter-
mined and loaded into WR12 and WR13. Next, the processor must select the clock source
for the baud rate generator by setting bit D1 of WR14. Finally, the baud rate generator is
enabled by setting bit D0 of WR14 to “1.”
Note that the first write to WR14 is not necessary after a hardware reset if the clock source
is the /RTxC pin. This is because a hardware reset automatically selects the /RTxC pin as
the baud rate generator clock source.
3.4 DATA ENCODING/DECODING
The ISCC provides four different data encoding methods, selected by bits D6 and D5 in
WR10. An example of these four encoding methods is shown in Figure 3-3. Any encoding
method may be used in any X1 mode in the ISCC, asynchronous or synchronous. The data
encoding selected is active even though the transmitter or receiver may be idling or dis-
abled. The data encoding methods are shown in Figure 3-3.
Table 3–8. Baud Rates for 2.4576 MHz Clock and 16x Clock Factor
Time Constant
Decimal Hex Baud Rate
0 0000 38400
2 0002 19200
6 0006 9600
14 000E 4800
30 001E 2400
62 003E 1200
126 007E 600
254 00FE 300
510 01FE 150
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