MK3234 View Datasheet(PDF) - Integrated Circuit Systems
Part Name
Description
Manufacturer
MK3234 Datasheet PDF : 4 Pages
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I CR O C LOC K
MK3234
Portable System Clock Synthesizer
Pin Assignment
CPUS2 1
X2 2
X1 3
VDD32 4
VDD 5
GND 6
32K 7
GND 8
16 CPUS1
15 CPUS0
14 CPUCLK
13 VDD
12 GND
11 14.3M
10 PD
9 PDCPU
CPU Clock Decoding
CPUS2 CPUS1 CPUS0 CPUCLK (MHz)
0
0
0
8.00
0
0
1
13.00
0
1
0
16.00
0
1
1
20.00
1
0
0
40.00
1
0
1
25.00
1
1
0
50.00
1
1
1
33.33
Frequency transitions will occur smoothly.
Pin Descriptions
Number
Name
Type Description
1
CPUS2
I Select 2 for CPUCLK frequencies. See Table above.
2
X2
O Crystal connection. Connect to 32.768 kHz crystal.
3
X1
I Crystal connection. Connect to 32.768 kHz crystal.
4
VDD32
P Separate power supply connection for 32.768kHz clock. Will operate to 2.0V.
5
VDD
P Connect to +3.3V or +5V. Must be the same voltage as pin 13.
6
GND
P Connect to ground.
7
32K
O 32.768 kHz square wave clock output.
8
GND
P Connect to ground.
9
PDCPU
I Power Down CPU clock output (stops low) when low.
10
PD
I Powers Down everything but 32kHz oscillator internally. 32kHz output buffer is off.
11
14.3M
O 14.318 MHz clock output. Do not use to drive video CRT controller.
12
GND
P Connect to ground.
13
VDD
P Connect to +3.3V or +5V. Must be the same voltage as pin 5.
14
CPUCLK
O CPUCLK output. See Table above.
15
CPUS0
I Select 0 for CPUCLK frequencies. See Table above.
16
CPUS1
I Select 1 for CPUCLK frequencies. See Table above.
Type: I = Input, O = output, P = power supply connection
Power Down status: Output clocks will stop in a low state when powered down
External Components
The MK3234 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1µF should be connected between VDD and GND, and VDD32 and GND, as close to the
MK3234 as possible. A series resistor of 10kΩ should be used on the VDD32 supply. A series termination
resistor of 33Ω may be used for each clock output, except the 32.768 kHz. For tuning the real time clock
output, use a 32.768 kHz crystal with a load capacitance of 12.5pF, and connect a 20pF±5% (NPO
dielectric) capacitor between each crystal pin and ground. The 32.768 kHz crystal must be connected as
close to the chip as possible. The 14.3 MHz output is not suitable for driving CRT displays. A separate
14.318 MHz crystal should be used at the input to the graphics controller chip. Consult MicroClock for a
recommended external circuit schematic.
MDS 3234 C
2
Revision 022798
Printed 11/16/00
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
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