DSP56002RC40 Motorola Inc, DSP56002RC40 Datasheet - Page 11

• Manufacturer Part Number: DSP56002RC40
• Description: 24-BIT DIGITAL SIGNAL PROCESSOR
• Manufacturer: Motorola Inc

PLL AND CLOCK
MOTOROLA
EXTAL
XTAL
CKOUT
CKP
PCAP
Signal
Name
Output
Output
Output
Input/
Signal
Input
Input
Type
Indeter-
during
minate
driven
driven
Reset
Input
Chip-
Chip-
Input
State
Table 1-4 PLL and Clock Signals
External Clock/Crystal Input—This input connects the internal
oscillator input to an external crystal or to an external oscillator.
Crystal Output—This output connects the internal crystal oscillator
output to an external crystal. If an external oscillator is used, XTAL
should be left unconnected.
PLL Output Clock—When the PLL is enabled and locked, this
signal provides a 50% duty cycle output clock signal synchronized
to the internal processor clock.
When the PLL is enabled and the Multiplication Factor is less than
or equal to 4, then CKOUT is synchronized to EXTAL.
When the PLL is disabled, the output clock at CKOUT is derived
from, and has the same frequency and duty cycle as, EXTAL.
Note:
PLL Output Clock Polarity Control—The value of this signal at
reset defines the polarity of the CKOUT output relative to EXTAL. If
CKP is pulled low by connecting through a resistor to ground,
CKOUT and EXTAL have the same polarity. Pulling CKP high by
connecting it through a resistor to V
to be inverse polarities. The polarity of CKOUT is latched at the end
of reset; therefore, any changes to CKP after deassertion of RESET
do not affect CKOUT polarity.
PLL Capacitor—This signal is used to connect the required external
filter capacitor to the PLL filter. Connect one end of the capacitor to
PCAP and the other to V
in Section 2 of this data sheet.
DSP56002/D, Rev. 3
For information about using the PLL Multiplication Factor,
see the
DSP56002 User’s Manual
Signal Description
CCP
. The value of the capacitor is specified
CC
causes CKOUT and EXTAL
.
Signal/Pin Descriptions
PLL and Clock
1-5