Samsung KS57C2308 Manual page 176

OSCILLATOR CIRCUITS
+ +
PROGRAMMING TIP — Setting the CPU Clock
To set the CPU clock to 0.95 µs at 4.19 MHz:
BITS
SMB
LD
LD
INSTRUCTION CYCLE TIMES
The unit of time that equals one machine cycle varies depending on whether the main system clock (fx) or a
subsystem clock (fxt) is used, and on how the oscillator clock signal is divided (by 4, 8, or 64). Table 6-2 shows
corresponding cycle times in microseconds.
Oscillation
Source
fx = 4.19 MHz
fxt = 32.768 kHz
6-6
EMB
15
A,#3H
PCON,A
Table 6-2. Instruction Cycle Times for CPU Clock Rates
Selected
CPU Clock
fx/64
fx/8
fx/4
fxt/4
Resulting Cycle Time (µs)
Frequency
65.5 kHz
524.0 kHz
1.05 MHz
8.19 kHz
KS57C2308/P2308/C2316/P2316
15.3
1.91
0.95
122.0