56F8322 Techncial Data, Rev. 10.0
134 Freescale Semiconductor
Preliminary
Because the device’s output signals have fast rise and fall times, PCB trace lengths should be minimal
Consider all device loads as well as parasitic capacitance due to PCB traces when calculating capacitance.
This is especially critical in systems with higher capacitive loads that could create higher transient currents
in the VDD and VSS circuits.
Take special care to minimize noise levels on the VREF, VDDA and VSSA pins
Because the Flash memory is programmed through the JTAG/EOnCE port, the designer should provide an
interface to this port to allow in-circuit Flash programming
12.3 Power Distribution and I/O Ring Implementation

Figure 12-1 illustrates the general power control incorporated in the 56F8322/56F8122. This chip

contains two internal power regulators. One of them is powered from the VDDA_OSC_PLL pin and cannot

be turned off. This regulator controls power to the internal clock generation circuitry. The other regulator

is powered from the VDD_IO pins and provides power to all of the internal digital logic of the core, all

peripherals and the internal memories. This regulator can be turned off, if an external VDD_CORE voltage

is externally applied to the VCAP pins.

In summary, the entire chip can be supplied from a single 3.3 volt supply if the large core regulator is

enabled. If the regulator is not enabled, a dual supply 3.3V/2.5V configuration can also be used.

Notes:

Flash, RAM and internal logic are powered from the core regulator ou tput
•V
PP1 and VPP2 are not connected in the customer system
All circuitry, analog and digital, shares a common VSS bus

Figure 12-1 Power Management

REG
CORE
VCAP
I/O ADC
VDD
VSS
OCS REG
VDDA_OSC_PLL
ROSC
VSSA_ADC
VDDA_ADC
VREFH
VREFP
VREFMID
VREFN
VREFLO