DSP56002RC40 Motorola Inc, DSP56002RC40 Datasheet - Page 12

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

Signal/Pin Descriptions
PLL and Clock
1-6
PINIT
PLOCK
Signal
Name
Output
Signal
Input
Type
Indeter-
during
minate
Reset
Input
State
Table 1-4 PLL and Clock Signals (Continued)
PLL Initialization Source—The value of this signal at reset defines
the value written into the PLL Enable (PEN) bit in the PLL control
register.
If PINIT is pulled high during reset, the PEN bit is written as a 1,
enabling the PLL and causing the DSP internal clocks to be derived
from the PLL VCO.
If PINIT is pulled low during reset, the PEN bit is written as a 0,
disabling the PLL and causing DSP internal clocks to be derived
from the clock connected to EXTAL.
PEN is written only at the deassertion of RESET and; therefore, the
value of PINIT is ignored after that time.
Phase and Frequency Lock—This output is generated by an
internal Phase Detector circuit. This circuit drives the output high
when:
The circuit drives the output low (deasserted) whenever the PLL is
enabled, but has not locked onto the proper phase and frequency.
Note:
•
•
DSP56002/D, Rev. 3
the PLL is disabled (the output clock is EXTAL and is
therefore in phase with itself), or
the PLL is enabled and is locked onto the proper phase
(based on the CKP value) and frequency of EXTAL.
PLOCK is a reliable indicator of the PLL lock state only after
the chip has exited the Reset state. During hardware reset,
the PLOCK state is determined by PINIT and the current
PLL lock condition.
Signal Description
MOTOROLA