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Device Overview
MFR4200 Data Sheet, Rev. 0
42
Freescale Semiconductor
As the CLKOUT signal can be disabled during internal resets, refer to
Section 2.4.4, “External Output Clock
” for more information on
CLKOUT
generation during external hard and internal resets
.
2.2.3.18
RESET# — External Reset
RESET# is an active-low control signal that acts as an input to initialize the CC to a known startup state.
2.2.3.19
INT_CC# — Interrupt Output
INT_CC# is an AMI and HCS12 interfaces interrupt request output signal. The CC may request a service
routine from the host to run. The interrupt is indicated by the logic level: it is asserted if the INT_CC#
outputs a logic "0" and negated if it outputs a logic "1".
The pin can be configured to provide either high or reduced output drive.
2.2.3.20
TEST
The TEST pin must be tied to VSS in all applications.
2.2.3.21
EXTAL/CC_CLK — Crystal Driver, External Clock Pin
This pin can act as a crystal driver pin (EXTAL) or as an external clock input pin (CC_CLK). On reset, the
device clock is derived from the input frequency on this pin. Refer to
Figure 2-3
for Pierce oscillator
connections and and
Figure 2-4
for external clock connections. See also
Chapter 6, “Oscillator (OSCV2)
”.
2.2.3.22
XTAL — Crystal Driver Pin
XTAL is a crystal driver pin. Refer to
Figure 2-3
for Pierce oscillator connections and and
Figure 2-4
for
external clock connections. See also
Chapter 6, “Oscillator (OSCV2)
”.
Figure 2-3. Pierce Oscillator Connections
Where:
Q = 40 MHz crystal
Rb is in the range 1M - 10 Mohms
Rs is a lower value, which can be 0 Ohms
C1 = C2
Oscillator supply output capacitor C3 = 220 nF
Refer to crystal manufacturer’s product specification for
recommended values
EXTAL
XTAL
VDDOSC
VSSOSC
Rs
Rb
Q
C2
C1
C3
VSSOSC
VSSOSC
MFR4200