MC68HC908GR8CFA Freescale Semiconductor, MC68HC908GR8CFA Datasheet - Page 123

• Manufacturer Part Number: MC68HC908GR8CFA
• Description: IC MCU FLSH 8BIT8MHZ 7.5K32-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GR8CFA

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 21
• Program Memory Size: 7.5KB (7.5K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

7.7 Interrupts
7.8 Special Modes
7.8.1 Wait Mode
MC68HC908GR8 — Rev 4.0
MOTOROLA
NOTE:
When the AUTO bit is set in the PLL bandwidth control register (PBWC),
the PLL can generate a CPU interrupt request every time the LOCK bit
changes state. The PLLIE bit in the PLL control register (PCTL) enables
CPU interrupts from the PLL. PLLF, the interrupt flag in the PCTL,
becomes set whether interrupts are enabled or not. When the AUTO bit
is clear, CPU interrupts from the PLL are disabled and PLLF reads as
logic 0.
Software should read the LOCK bit after a PLL interrupt request to see
if the request was due to an entry into lock or an exit from lock. When the
PLL enters lock, the VCO clock, CGMVCLK, divided by two can be
selected as the CGMOUT source by setting BCS in the PCTL. When the
PLL exits lock, the VCO clock frequency is corrupt, and appropriate
precautions should be taken. If the application is not frequency sensitive,
interrupts should be disabled to prevent PLL interrupt service routines
from impeding software performance or from exceeding stack
limitations.
Software can select the CGMVCLK divided by two as the CGMOUT
source even if the PLL is not locked (LOCK = 0). Therefore, software
should make sure the PLL is locked before setting the BCS bit.
The WAIT instruction puts the MCU in low power-consumption standby
modes.
The WAIT instruction does not affect the CGMC. Before entering wait
mode, software can disengage and turn off the PLL by clearing the BCS
and PLLON bits in the PLL control register (PCTL) to save power. Less
power-sensitive applications can disengage the PLL without turning it
off, so that the PLL clock is immediately available at WAIT exit. This
would be the case also when the PLL is to wake the MCU from wait
Freescale Semiconductor, Inc.
For More Information On This Product,
Clock Generator Module (CGMC)
Go to: www.freescale.com
Clock Generator Module (CGMC)
Technical Data
Interrupts
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