Z51F0410 Datasheet, PDF (72/184 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F0410
Product Specification
4. Peripheral Hardware
4.1 Clock Generator
4.1.1 Overview
As shown in Figure 4.1, the clock generator produces the basic clock pulses which provide the
system clock to be supplied to the CPU and the peripheral hardware. It contains main-frequency clock
oscillator. The system clock operation can be easily obtained by attaching a crystal between the XIN
and XOUT pin, respectively. The system clock can also be obtained from the external oscillator. In
this case, it is necessary to put the external clock signal into the XIN pin and open the XOUT pin. The
default system clock is INT-RC Oscillator and the default division rate is one. In order to stabilize
system internally, use 128 KHz ring-oscillator (±50%) for BIT and WDT.
- Calibrated Internal RC Oscillator (8 MHz / ±1%)
. INT-RC OSC/1 (Default system clock)
. INT-RC OSC/2 (4 MHz)
. INT-RC OSC/4 (2 MHz)
. INT-RC OSC/8 (1 MHz)
- Crystal Oscillator (1~8 MHz)
- Sub-Clock Crystal Oscillator (32.768 KHz)
- Internal Ring-Oscillator (128 KHz / ±50%)
4.1.2 Block Diagram
XIN
XOUT
SUBXIN
SUBXOUT
PDOWN
Main
OSC
SUB
OSC
WT
fXIN
fSUB
fRingRC
fINTRC
1/1
1/2
Divider 1/4
1/8
Clock
Change
DCLK _System
ClockGen.
SCLK
(Core, System,
Peripherals)
System
Clock
Masking Control
INT-RC
OSC
(8MHz)
Ring-OSC
(128KHz)
PDOWN
WONS
BIT
Overflow
BIT
WDT
Figure 4.1 Clock Generator Block Diagram
PS029502-0212
PRELIMINARY
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