MC68HC908LJ12CFU Freescale Semiconductor, MC68HC908LJ12CFU Datasheet - Page 212

• Manufacturer Part Number: MC68HC908LJ12CFU
• Description: IC MCU 12K FLASH 8MHZ 64-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LJ12CFU

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: IRSCI, SPI
• Peripherals: LCD, LVD, POR, PWM
• Number Of I /o: 32
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Real Time Clock (RTC)
12.4 Functional Description
Technical Data
212
The RTC module provides clock indications in seconds, minutes, and
hours; calendar indications in day-of-week, day-of-month, month, and
year; with automatic adjustment for month and leap year. Reading the
clock and calendar registers return the current time and date. Writing to
these registers set the time and date, and the counters will continue to
count from the new settings.
The alarm interrupt is set for the hour and minute. When the hour and
minute counters matches the time set in the alarm hour and minute
registers, the alarm flag is set. The alarm can be configured to generate
a CPU interrupt request.
A 1/100 seconds chronograph counter is provided for timing
applications. This counter can be independently enabled or disabled,
and cleared at any time.
RTC module interrupts include the alarm interrupt and seven periodic
interrupts from the clock counters.
For proper RTC module operation, one of the following oscillator
frequencies (CGMXCLK) must be used:
Configuring the XTL[2:0] bits in the RTC control register 2 selects the
appropriate prescalers and dividers to divide CGMXCLK down to the
basic 1Hz clock for driving the clock counters.
Figure 12-2
•
•
•
•
•
32.768 kHz
32.000 kHz
38.400 kHz
64.000 kHz
76.800 kHz
shows the structure of the RTC module.
Real Time Clock (RTC)
MC68HC908LJ12
Freescale Semiconductor
—
Rev. 2.1