![](http://datasheet.mmic.net.cn/30000/MK3230-02SLFTR_datasheet_2794575/MK3230-02SLFTR_2.png)
MK3230
Portable System Clock Synthesizer
MDS 3230 F
2
Revision 022798
Printed 11/16/00
Integrated Circuit Systems, Inc.525 Race StreetSan JoseCA95126(408)295-9800telwww.icst.com
I C R O
C LOC K
Pin Assignment
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
24M
O
24 MHz floppy (or super I/O) clock output.
8
32K
O
32.768 kHz square wave clock output.
9
KBOUT
O
Keyboard clock output. Either 12MHz (-01) or 16MHz (-02)
10
PD24+KBD
I
Power Down 24M+keyboard. Shuts off both clock outputs (pins 7,9) when low.
11
14.3M
O
14.318 MHz system clock output. Do not drive a CRT PLL device with this output.
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.
Pin Descriptions
CPUS2 CPUS1 CPUS0 CPUCLK (MHz)
0
Off+14M off
0
1
80.00
0
1
0
25.00
0
1
66.66
1
0
20.00
1
0
1
50.00
1
0
33.33
1
4.00
CPU Clock Decoding
Type: I = Input, O = output, P = power supply connection
Power Down status: Output clocks will stop in a low state when powered down
1
8
9
16
2
3
4
5
6
7
10
11
12
13
14
15
CPUS1
PD24+KBD
KBOUT
CPUCLK
14.3M
CPUS0
VDD
GND
CPUS2
32K
X2
GND
24M
VDD32
VDD
X1
External Components
The MK3230 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1F should be connected between VDD and GND, and VDD32 and GND, as close to the
MK3230 as possible. A 10k
series resistor should be used to filter the VDD32 pin. A series termination
resistor of 33
may be used for each clock output. The device does not require (nor do we recommend)
capacitors connected to the crystal pins. The 32.768 kHz crystal must be connected as close to the chip as
possible. See Application Brief MAB02 for a discussion on tuning for use on a real time clock (RTC).
Frequency transitions (except going to/from
off) will occur smoothly, and are compatible
with all 486 processors.