Clock Circuit - Samsung S3F84B8 User Manual

S3F84B8_UM_REV 1.00
7

CLOCK CIRCUIT

7.1 OVERVIEW OF CLOCK CIRCUIT
Using the Smart option (3FH.1– .0 in ROM), you can select the internal RC oscillator, external RC oscillator, or
external oscillator. In internal oscillator, X
An internal RC oscillator can provide a typical frequency of 8MHz or 0.5MHz for S3F84B8, depending on the
Smart option. On the other hand, an external RC oscillator can provide a typical frequency of 8MHz clock for
S3F84B8.
An internal capacitor supports the RC oscillator circuit. In addition, an external crystal or ceramic oscillation source
provides 10MHz clock (maximum). The X
and
Figure 7-1 Figure 7-2
you use external oscillator, P0.0 and P0.1 must be set to output port to prevent current consumption.
Figure 7-1
(P0.0) and X
IN
and X
IN
show a simplified external RC oscillator and crystal/ceramic oscillator circuits. When
X IN
R
X
OUT
Main Oscillator Circuit (RC Oscillator with Internal Capacitor)
C1
C2
Figure 7-2 Main Oscillator Circuit (Crystal/Ceramic Oscillator)
(P0.1) can be used by normal I/O pins.
OUT
pins connect oscillation source to the on-chip clock circuit.
OUT
S3F84B8
X
IN
S3F84B8
X
OUT
7-1
7 CLOCK CIRCUIT