mc9s12c32mpb16 Freescale Semiconductor, Inc, mc9s12c32mpb16 Datasheet - Page 51

• Manufacturer Part Number: mc9s12c32mpb16
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

1.3.4
1.3.4.1
EXTAL and XTAL are the crystal driver and external clock pins. On reset all the device clocks are derived
from the EXTAL input frequency. XTAL is the crystal output.
1.3.4.2
RESET is an active low bidirectional control signal that acts as an input to initialize the MCU to a known
start-up state. It also acts as an open-drain output to indicate that an internal failure has been detected in
either the clock monitor or COP watchdog circuit. External circuitry connected to the RESET pin should
not include a large capacitance that would interfere with the ability of this signal to rise to a valid logic one
within 32 ECLK cycles after the low drive is released. Upon detection of any reset, an internal circuit
drives the RESET pin low and a clocked reset sequence controls when the MCU can begin normal
processing.
1.3.4.3
This pin is reserved for test and must be tied to V
1.3.4.4
Dedicated pin used to create the PLL loop filter. See CRG BUG for more detailed information.PLL loop
filter. Please ask your Motorola representative for the interactive application note to compute PLL loop
filter elements. Any current leakage on this pin must be avoided.
1.3.4.5
The BKGD / TAGHI / MODC pin is used as a pseudo-open-drain pin for the background debug
communication. In MCU expanded modes of operation when instruction tagging is on, an input low on
this pin during the falling edge of E-clock tags the high half of the instruction word being read into the
instruction queue. It is also used as a MCU operating mode select pin at the rising edge during reset, when
the state of this pin is latched to the MODC bit.
Freescale Semiconductor
Detailed Signal Descriptions
EXTAL, XTAL — Oscillator Pins
RESET — External Reset Pin
TEST / V
XFC — PLL Loop Filter Pin
BKGD / TAGHI / MODC — Background Debug, Tag High, and Mode Pin
PP
— Test Pin
Figure 1-10. PLL Loop Filter Connections
MC9S12C-Family / MC9S12GC-Family
MCU
XFC
Rev 01.23
SS
V
Chapter 1 MC9S12C and MC9S12GC Device Overview (MC9S12C128)
DDPLL
in all applications.
R
C
0
S
V
DDPLL
C
P
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