M55800A Atmel Corporation, M55800A Datasheet - Page 76

• Manufacturer Part Number: M55800A
• Manufacturer: Atmel Corporation

Specifications of M55800A

• Flash (kbytes): 0 Kbytes
• Pin Count: 176
• Max. Operating Frequency: 33 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 58
• Ext Interrupts: 58
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 3
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 72
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 8
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.3/5.0
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

13.2.4
76
AT91M5880A
Updating Time/Calendar
Note:
To update any of the time/calendar fields, the user must first stop the RTC by setting the corre-
sponding field in the Mode Register (RTC_MR). 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 Register
(RTC_SR). Once the bit reads 1 (the user must clear this status bit by writing ACKUPD to 1 in
RTC_SCR), the user can write to the appropriate register.
Once the update is finished, the user must reset (0) UPDTIM and/or UPDCAL in the Mode Reg-
ister (RTC_MR).
When programming the calendar fields, the time fields remain enabled. This avoids a time slip in
case the user stays in the calendar update phase for several tens of seconds or more.
6. Hour (BCD check, 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.
1745F–ATARM–06-Sep-07