AT91RM9200-CI-002 Atmel, AT91RM9200-CI-002 Datasheet - Page 307

• Manufacturer Part Number: AT91RM9200-CI-002
• Description: IC ARM9 MCU 256 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91RM9200-CI-002

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: POR
• Number Of I /o: 122
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

25.4.5
1768I–ATARM–09-Jul-09
Updating Time/Calendar
value is programmed. This avoids any further side effects in the hardware. The same procedure
is done for the alarm.
The following checks are performed:
Note:
To update any of the time/calendar fields, the user must first stop the RTC by setting the corre-
sponding field in the Control Register. Bit UPDTIM must be set to update time fields (hour,
minute, second) and bit UPDCAL must be set to update calendar fields (century, year, month,
date, day).
Then the user must poll or wait for the interrupt (if enabled) of bit ACKUPD in the Status Regis-
ter. Once the bit reads 1, the user must clear this status bit by writing ACKUPD to 1 in
RTC_SCCR, and write to the appropriate register.
Once the update is finished, the user must reset (0) UPDTIM and/or UPDCAL in the Control
Register.
The time and date are stopped when entering the programming mode.
It is highly recommended to prepare all the fields to update prior to entering the programming
mode, to avoid a time slip in case the user would stay in the calendar update phase for several
tens of seconds or more.
In successive update operations, the user must wait at least one second after resetting the
UPDTIM/UPDCAL bit in the RTC_CR (Control Register) before setting these bits again. This is
done by waiting for the SEC flag in the Status Register before setting UPDTIM/UPDCAL bit.
After resetting UPDTIM/UPDCAL, the SEC flag must also be cleared.
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, check validity regarding “date”)
5. Day (check range 1 - 7)
6. Hour (BCD checks: in 24-hour mode, check range 00 - 23 and check that AM/PM flag is
7. Minute (check BCD and range 00 - 59)
8. Second (check BCD and range 00 - 59)
not set if RTC is set in 24-hour mode; in 12-hour mode check range 01 - 12)
If the 12-hour mode is selected by means of the RTC_MODE register, a 12-hour value can be pro-
grammed and the returned value on RTC_TIME will be the corresponding 24-hour value. The
entry control checks the value of the AM/PM indicator (bit 22 of RTC_TIME register) to determine
the range to be checked.
AT91RM9200
307