Intel UPI-C42 Computer Hardware User Manual


 
UPI-C42UPI-L42
DRIVING FROM AN EXTERNAL SOURCE
290414–18
NOTE
See XTAL1 Configuration Table
290414–19
Rise and Fall Times Should Not
Exceed 10 ns Resistors to V
CC
are Needed to Ensure V
IH
e
35V
if TTL Circuitry is Used
LC OSCILLATOR MODE
L C NOMINAL
f
e
1
2q
0
LC
45 H 20 pF 52 MHz
120 H 20 pF 32 MHz
C
e
C
a
3Cpp
2
Cpp
j
5–10pF
Pin-to-Pin Capacitance
290414–20
Each CShould beApproximately 20pF includingStray Capacitance
CRYSTAL OSCILLATOR MODE
290414–21
C1 5 pF (STRAY 5 pF)
C2 (CRYSTAL
a
STRAY) 8 pF
C3 20–30 pF INCLUDING STRAY
Crystal Series Resistance Should
be Less Than 30X at 125 MHz
XTAL1 Configuration Table
XTAL1 Connection
1) to Ground
2) 10 KX Resistor
3) Not Connected
to Ground
Not recommended for CHMOS Recommended configuration for Low power configuration
designs Causes approximately designs which will use both recommended for CHMOS only
16 mA of additional current flow NMOS and CHMOS parts This designs to provide lowest
through the XTAL1 pin on UPI- configuration limits the additional possible power consumption
C42 and approximately 11 mA of current through the XTAL1 pin to This configuration will not work
additional current through XTAL1 approximately 1 mA while with the NMOS device
on the UPI-L42 maintaining compatibility with the
NMOS device
20