MC908LJ24CPBE Freescale Semiconductor, MC908LJ24CPBE Datasheet - Page 226

• Manufacturer Part Number: MC908LJ24CPBE
• Description: IC MCU 24K FLASH 8MHZ SPI 64LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908LJ24CPBE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, IRSCI, SPI
• Peripherals: LCD, LVD, POR, PWM
• Number Of I /o: 40
• Program Memory Size: 24KB (24K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 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-LQFP
• Processor Series: HC08LJ
• Core: HC08
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: SCI/SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 48
• Number Of Timers: 4
• Operating Supply Voltage: 3.3 V, 5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: FSICEBASE, M68EML08LJLKE, ZK-HC08LX-A, M68CBL05CE
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 6-ch x 10-bit
• Controller Family/series: HC08
• No. Of I/o's: 40
• Ram Memory Size: 768Byte
• Cpu Speed: 8MHz
• No. Of Timers: 2
• Embedded Interface Type: I2C, SCI, SPI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Real Time Clock (RTC)
12.7.1 Calibration Error
Data Sheet
226
–30 ≤ E ≤ –16
–15 ≤ E ≤ –1
16 ≤ E ≤ 30
1 ≤ E ≤ 15
E
E = 0
Table 12-2. Compensation Algorithm for Different Values of E
CGMXCLK Cycles
(|E| – 15) × 32766
(|E| – 15) × 32770
A negative E-value indicates the number of CGMXCLK cycles that
needs to be subtracted, because the CGMXCLK is slower than the ideal
32.768kHz; 32768 CGMXCLK cycles will be more longer than 1-second.
A positive E-value indicates the number of CGMXCLK cycles that needs
to be added, because the CGMXCLK is faster than the ideal 32.768kHz;
32768 CGMXCLK cycles will be more shorter than 1-second.
If the time difference is more than 31 CGMXCLK cycles, the E-register
will overflow, causing the EVOL flag to be set. The maximum (+30) or
minimum (–30) value will remain in the E-register.
After calibration, with the E-value stored in the calibration data register,
clock compensation is only enabled when the COMEN bit is set in
RTCCR2. As the E-value is the time difference for 15 seconds, the
CGMXCLK is modified for every 15-second intervals. The CGMXCLK
additions and subtractions are simulated using programmable dividers,
therefore, the compensated clock does not have the same period within
the 15-second, but is consistent for every 15-second periods. See
12-2
During clock calibration, the reference signal to the CALIN pin is not
synchronized to the CGMXCLK being measured. A maximum
inaccuracy of minus 1.5×CGMXCLK period or plus 1×CGMXCLK period
will be introduced to the time difference measured.
Number of
|E| × 32767
|E| × 32769
and
No compensation is required: Divider is 32768 throughout.
Period A
Figure
Real Time Clock (RTC)
12-4.
CGMXCLK
Divider A
32766
32767
32769
32770
CGMXCLK Cycles
(30 – |E|) × 32767
(15 – |E|) × 32768
(15 – |E|) × 32768
(30 – |E|) × 32769
Number of
MC68HC908LJ24/LK24 — Rev. 2.1
Period B
Freescale Semiconductor
CGMXCLK
Divider B
32767
32768
32769
32769
Table