cp3ub17 National Semiconductor Corporation, cp3ub17 Datasheet - Page 51

• Manufacturer Part Number: cp3ub17
• Description: Reprogrammable Connectivity Processor With Usb Interface
• Manufacturer: National Semiconductor Corporation

11.0 Triple Clock and Reset
The Triple Clock and Reset module generates a 12 MHz
Main Clock and a 32.768 kHz Slow Clock from external
crystal networks or external clock sources. It provides vari-
ous clock signals for the rest of the chip. It also provides the
main system reset signal, a power-on reset function, Main
Main Clock
Reset
X1CKI
X1CKO
X2CKI
X2CKO
(x3, x4, or x5)
High Frequency
Low Frequency
Oscillator
Oscillator
PLL
TWM (Invalid Watchdog Service)
Flash Interface (Program/Erase Busy)
External Reset
Figure 3. Triple Clock and Reset Module
Stop Main Osc.
by 2
Div.
Slow Clock Prescaler
Preset
Power-On-Reset
Start-Up-Delay
Start-Up-Delay
Module (POR)
14-Bit Timer
8-Bit Timer
Stop PLL
4-Bit Aux1
4-Bit Aux2
51
Prescaler
Prescaler
Prescaler
Preset
8-Bit
Clock prescalers to generate two additional low-speed
clocks, and a 32-kHz oscillator start-up delay.
Figure 3 is block diagram of the Triple Clock and Reset mod-
ule.
Fast Clock
Prescaler
Prescaler
Time-out
4-Bit
Module
Reset
Stop Main Osc
Good Main Clock
Auxiliary Clock 1
Auxiliary Clock 2
Slow Clock
Slow Clock
Select
Good Slow Clock
Stop Slow Osc
Bypass
32 kHz Osc
System Clock
Fast Clock
Select
PLL Clock
Bypass PLL
Good PLL Clock
Stop PLL
Device Reset
Stretched
Reset
DS006
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