gc80c520a CORERIVER Semiconductor, gc80c520a Datasheet - Page 70

• Manufacturer Part Number: gc80c520a
• Description: Midas1.0 Family Mask Rom/eprom/romless 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

6.2.10 Clock Circuit (On-chip oscillators)
The MiDAS1.0 family supports two clock configurations as shown in Figure 6-35: 1) crystal oscillator, and
2) oscillator module.
The MiDAS1.0 family has the on-chip oscillator circuitry, which is a single stage linear inverter intended
for use as a crystal-controlled, positive reactance oscillator. Software can turn off its oscillator by writing a
1 to the PD bit in PCON as shown in Figure 6-36. Typically, C
quartz crystal, and C
The load capacitance of the crystal oscillator is dependent on the operating frequency as shown in Figure
To drive the processor with an external clock source, apply the external clock signal to XTAL1 and leave
XTAL2 float, as shown in Figure 6-36.
6-37. Table 6-13 shows the recommended load capacitance for the various frequencies.
Load Capacitance C
Table 6-13 Recommended load capacitance in the crystal oscillator (V
L
= 47 pF when a ceramic resonator is used.
Crystal Oscillator
Figure 6-35 Configuration for Clock Generators
L
XTAL2
XTAL1
~ 11.0592
MiDAS
47pF
Page 70 of 187
Oscillator Module
Oscillator Module
Crystal Oscillator [MHz]
OSC
L
22.1184
= 30 pF when the feedback element is a
XTAL2
XTAL1
20pF
Functional Description
MiDAS
DD
40.0000
10pF
= 5V)