st2604b Sitronix Technology Corporation, st2604b Datasheet - Page 27

• Manufacturer Part Number: st2604b
• Description: 8-bit Integrated Microcontroller
• Manufacturer: Sitronix Technology Corporation

<System clock switching from OSC to OSCX>
Cause warm-up time is different when OSC is RC-OSC or X’ tal.
To make sure the system clock has switched to OSCX, or error will happen.
Sample code, please follow up…
LDA
ORA
STA
NOP
NOP
NOP
BBR7 SYS,$ ; branch self until OSC is changed to OSCX
<Measure RC-OSC system clock>
Since programmer wants to measure the system clock when using RC-OSC, please follow up.
Please connect a 3K-Ohm resistor between Vdd and XIO. You can get a periodic signal output from the XIO
pin. It's RC osc signal.
<IrDA mode application note>
Since IrDA has strictly protocol when transmit/receive data.
We suggest programmers use X’tal to be system clock instead of RC-OSC if IrDA signals are needed.
Programmer can use ceramic-OSC to gain some profit since it’ s cheaper than X’ tal.
SYS
#80H
SYS
;switch OSC to OSCX
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ST2604B