Zilog Z16C35 Bedienungsanleitung PDF herunterladen (Seite 37)

ISCC

User Manual

UM011002-0808

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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Zilog Z16C35 Bedienungsanleitung Seite 37