PIC24FJ256GA110-I/PT Microchip Technology, PIC24FJ256GA110-I/PT Datasheet - Page 209

• Manufacturer Part Number: PIC24FJ256GA110-I/PT
• Description: IC PIC MCU FLASH 256K 100TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 24Fr

Specifications of PIC24FJ256GA110-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 256KB (85.5K x 24)
• Package / Case: 100-TFQFP
• Core Processor: PIC
• Core Size: 16-Bit
• Speed: 32MHz
• Connectivity: I²C, PMP, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 85
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC24FJ
• Core: PIC
• Data Bus Width: 16 bit
• Data Ram Size: 16 KB
• Interface Type: I2C/SPI/UART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 85
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52713-733, 52714-737, 53276-922, EWDSPIC
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, DM240001, DM240011
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 16-ch x 10-bit
• Package: 100TQFP
• Device Core: PIC
• Family Name: PIC24
• Maximum Speed: 32 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 876-1004 - PIC24 BREAKOUT BOARDMA240015 - BOARD MCV PIM FOR 24F256GADM240011 - KIT STARTER MPLAB FOR PIC24F MCUAC164333 - MODULE SKT FOR PM3 100QFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

REGISTER 18-10:
18.2
The real-time crystal input can be calibrated using the
periodic auto-adjust feature. When properly calibrated,
the RTCC can provide an error of less than 3 seconds
per month. This is accomplished by finding the number
of error clock pulses for one minute and storing the
value into the lower half of the RCFGCAL register. The
8-bit signed value loaded into the lower half of
RCFGCAL is multiplied by four and will be either added
or subtracted from the RTCC timer, once every minute.
Refer to the steps below for RTCC calibration:
1.
2.
EQUATION 18-1:
© 2008 Microchip Technology Inc.
bit 15
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 15
bit 14-12
bit 11-8
bit 7
bit 6-4
bit 3-0
Error (Clocks per Minute) = (Ideal Frequency† –
Measured Frequency) * 60 = Clocks per Minute
Using another timer resource on the device, the
user must find the error of the 32.768 kHz
crystal.
Once the error is known, it must be converted to
the number of error clock pulses per minute and
loaded into the RCFGCAL register.
U-0
U-0
—
—
Calibration
† Ideal frequency = 32,768 Hz
Unimplemented: Read as ‘0’
MINTEN2:MINTEN0: Binary Coded Decimal Value of Minute’s Tens Digit; Contains a value from 0 to 5
MINONE3:MINONE0: Binary Coded Decimal Value of Minute’s Ones Digit; Contains a value from 0 to 9
Unimplemented: Read as ‘0’
SECTEN2:SECTEN0: Binary Coded Decimal Value of Second’s Tens Digit; Contains a value from 0 to 5
SECONE3:SECONE0: Binary Coded Decimal Value of Second’s Ones Digit; Contains a value from 0 to 9
SECTEN2
MINTEN2
R/W-x
R/W-x
ALMINSEC: ALARM MINUTES AND SECONDS VALUE REGISTER
RTCC CALIBRATION
W = Writable bit
‘1’ = Bit is set
SECTEN1
MINTEN1
R/W-x
R/W-x
SECTEN0
MINTEN0
PIC24FJ256GA110 FAMILY
R/W-x
R/W-x
Preliminary
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
SECONE3
MINONE3
R/W-x
R/W-x
3.
4.
Writes to the lower half of the RCFGCAL register
should only occur when the timer is turned off, or
immediately after the rising edge of the seconds pulse.
Note:
a) If the oscillator is faster then ideal (negative
result form step 2), the RCFGCAL register value
needs to be negative. This causes the specified
number of clock pulses to be subtracted from
the timer counter once every minute.
b) If the oscillator is slower then ideal (positive
result from step 2) the RCFGCAL register value
needs to be positive. This causes the specified
number of clock pulses to be subtracted from
the timer counter once every minute.
Divide the number of error clocks per minute by
4 to get the correct CAL value and load the
RCFGCAL register with the correct value.
(Each 1-bit increment in CAL adds or subtracts
4 pulses).
It is up to the user to include in the error
value the initial error of the crystal, drift
due to temperature and drift due to crystal
aging.
SECONE2
MINONE2
R/W-x
R/W-x
x = Bit is unknown
SECONE1
MINONE1
R/W-x
R/W-x
DS39905B-page 207
SECONE0
MINONE0
R/W-x
R/W-x
bit 8
bit 0