MC68HC908MR8CFA Freescale Semiconductor, MC68HC908MR8CFA Datasheet - Page 130

• Manufacturer Part Number: MC68HC908MR8CFA
• Description: IC MCU 8K FLASH 8MHZ PWM 32-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908MR8CFA

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 16
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 7x10b
• 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: -

Clock Generator Module (CGM)
Technical Data
130
ACQ — Acquisition Mode Bit
XLD — Crystal Loss Detect Bit
PBWC Bits 3–0 — Reserved for Test
When the AUTO bit is set, ACQ is a read-only bit that indicates
whether the PLL is in acquisition mode or tracking mode. When the
AUTO bit is clear, ACQ is a read/write bit that controls whether the
PLL is in acquisition or tracking mode.
In automatic bandwidth control mode (AUTO = 1), the last-written
value from manual operation is stored in a temporary location and is
recovered when manual operation resumes. Reset clears this bit,
enabling acquisition mode.
When the VCO output, CGMVCLK, is driving CGMOUT, this
read/write bit can indicate whether the crystal reference frequency is
active or not. To check the status of the crystal reference, follow these
steps:
The crystal loss detect function works only when the BCS bit is set,
selecting CGMVCLK to drive CGMOUT. When BCS is clear, XLD
always reads as logic 0.
These bits enable test functions not available in user mode. To ensure
software portability from development systems to user applications,
software should write 0s to PBWC[3:0] whenever writing to PBWC.
1. Write a logic 1 to XLD.
2. Wait N × 4 cycles. (N is the VCO frequency multiplier.)
3. Read XLD.
1 = Tracking mode
0 = Acquisition mode
1 = Crystal reference is not active.
0 = Crystal reference is active.
Clock Generator Module (CGM)
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor