AT91M55800A-33CJ Atmel, AT91M55800A-33CJ Datasheet - Page 75

• Manufacturer Part Number: AT91M55800A-33CJ
• Description: IC ARM MCU 16BIT 176BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91M55800A-33CJ

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 58
• Program Memory Type: ROMless
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 176-LFBGA
• Processor Series: AT91Mx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 8 KB
• Interface Type: EBI, SPI, USART
• Maximum Clock Frequency: 33 MHz
• Number Of Programmable I/os: 58
• Number Of Timers: 10 bit
• Operating Supply Voltage: 3 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91EB55
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• On-chip Dac: 8 bit, 2 Channel
• Cpu Family: AT91
• Device Core: ARM7TDMI
• Device Core Size: 32b
• Frequency (max): 33MHz
• Program Memory Size: Not Required
• Total Internal Ram Size: 8KB
• # I/os (max): 58
• Number Of Timers - General Purpose: 6
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 2.7V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 176
• Package Type: BGA
• For Use With: AT91EB55 - KIT EVAL FOR ARM AT91M55800A
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

13.2
13.2.1
13.2.2
13.2.3
1745F–ATARM–06-Sep-07
Functional Description
Timing
Alarm
Error Checking
The RTC provides a full Binary-Coded Decimal (BCD) clock which includes century (19/20), year
(with leap years), month, date, day, hours, minutes and seconds.
The valid year range is 1900 to 2099, a two-hundred year Gregorian calendar achieving full Y2K
compliance.
The RTC can operate in 24-hour mode or in 12-hour mode with an AM/PM indicator.
Corrections for leap years are included (all years divisible by 4 being leap years, including year
2000). This is correct up to the year 2099.
The RTC is updated in real-time at one second intervals in normal mode for the counters of sec-
onds, at 1 minute intervals for the counter of minutes and so on.
Due to the asynchronous operation of the RTC with respect to the rest of the chip, to be certain
that the value read in the RTC registers (century, year, month, date, day, hours, minutes, sec-
onds) are valid and stable, it is necessary to read these registers twice. If the data is the same
both times, then it is valid. Therefore, a minimum of two and a maximum of three accesses is
required.
The RTC has five programmable fields with which to program an alarm: MONTH and DATE in
the Calendar Alarm Register (RTC_CAR), and SEC, MIN and HOUR in the Time Alarm Register
(RTC_TAR). Each of these fields can be enabled or disabled using the bits MTHEN, DATEN,
SECEN, MINEN, HOUREN to match the alarm condition.
A verification on user interface data is performed when accessing the century, year, month,
date, day, hours, minutes, seconds and alarms. A check is performed on illegal BCD entries
such as illegal date of the month with regards to the year and century configured.
If one of the time fields is not correct, the data is not loaded into the register/counter and a flag is
set in the Valid Entry Register (RTC_VER). This flag cannot be reset by the user. It is reset as
soon as an acceptable value is programmed. This avoids any further side effects in the hard-
ware. The same processing is done for the alarm.
The following checks are processed:
• If all the fields are enabled, an alarm flag is generated (the corresponding flag is asserted
• If only the “seconds” field is enabled, then an alarm is generated every minute.
• Depending on the combination of fields enabled, a large number of possibilities are available
1. Century (check if it is in range 19 - 20)
2. Year (BCD entry check)
3. Date (check range 01 - 31)
4. Month (check if it is in BCD range 01 - 12,
5. Day (check range 1 - 7)
and an interrupt generated if enabled) at a given month, date, hour, minute and second.
to the user ranging from minutes to 365/366 days.
check validity regarding “date”)
AT91M5880A
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