Signal Pins
Table 2-2 Signal and Package Information for the 144-Pin LQFP
State
Signal Name
Pin No.
Type
During
Reset
Signal Description
VSSA_ADC
OCR_DIS
103
79
Supply
Input
ADC Analog Ground — This pin supplies an analog ground to the
ADC modules.
Input
On-Chip Regulator Disable —
Tie this pin to VSS to enable the on-chip regulator
Tie this pin to VDD to disable the on-chip regulator
This pin is intended to be a static DC signal from power-up to
shut down. Do not try to toggle this pin for power savings
during operation.
VCAP
VCAP
VCAP
1
2
3
51
128
83
Supply
Supply
VCAP1 - 4 — When OCR_DIS is tied to VSS (regulator enabled),
connect each pin to a 2.2µF or greater bypass capacitor in order to
bypass the core logic voltage regulator, required for proper chip
operation. When OCR_DIS is tied to VDD (regulator disabled),
these pins become VDD_CORE and should be connected to a
regulated 2.5V power supply.
VCAP4
15
Note: This bypass is required even if the chip is powered with
an external supply.
V
PP1
125
2
Input
Input
Input
Input
VPP1 - 2 — These pins should be left unconnected as an open
circuit for normal functionality.
VPP
2
CLKMODE
87
Clock Input Mode Selection — This input determines the function
of the XTAL and EXTAL pins.
1 = External clock input on XTAL is used to directly drive the input
clock of the chip. The EXTAL pin should be grounded.
0 = A crystal or ceramic resonator should be connected between
XTAL and EXTAL.
EXTAL
XTAL
82
81
Input
Input
External Crystal Oscillator Input — This input can be connected
to an 8MHz external crystal. Tie this pin low if XTAL is driven by an
external clock source.
Input/
Chip-driven Crystal Oscillator Output — This output connects the internal
Output
crystal oscillator output to an external crystal.
If an external clock is used, XTAL must be used as the input and
EXTAL connected to GND.
The input clock can be selected to provide the clock directly to the
core. This input clock can also be selected as the input clock for
the on-chip PLL.
56F8366 Technical Data, Rev. 2.0
Freescale Semiconductor
Preliminary
19
FREESCALE [ Freescale ]
