LPC2468FBD208,551 NXP Semiconductors, LPC2468FBD208,551 Datasheet - Page 656

• Manufacturer Part Number: LPC2468FBD208,551
• Description: IC ARM7 MCU FLASH 512K 208-LQFP
• Manufacturer: NXP Semiconductors
• Series: LPC2400r

Specifications of LPC2468FBD208,551

• Program Memory Type: FLASH
• Program Memory Size: 512KB (512K x 8)
• Package / Case: 208-LQFP
• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 72MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 160
• Ram Size: 98K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: LPC24
• Core: ARM7TDMI-S
• Data Bus Width: 16 bit, 32 bit
• Data Ram Size: 98 KB
• Interface Type: CAN/I2S/ISP/SSP/UART/USB
• Maximum Clock Frequency: 72 MHz
• Number Of Programmable I/os: 160
• Number Of Timers: 6
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2, IRD-LPC2468-DEV, SAB-TFBGA208, KSK-LPC2468-PL
• Development Tools By Supplier: OM10100
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• On-chip Dac: 1-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 622-1025 - KIT DEV IND REF DESIGN LPC2468622-1024 - BOARD SCKT ADAPTER FOR TFBGA208568-4358 - DISPLAY QVGA TFT FOR OM10100568-4309 - BOARD EXTENSION LPCSTICK568-4308 - EVAL LPC-STICK WITH LPC2468MCB2400U - BOARD EVAL MCB2400 + ULINK2MCB2400 - BOARD EVAL FOR NXP LPC246X SER622-1005 - USB IN-CIRCUIT PROG ARM7 LPC2K
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 568-4261; 935282457551; LPC2468FBD208-S

NXP Semiconductors
UM10237_4
User manual
6.7.1 Reference Clock Divider (Prescaler)
6.6 Alarm output
6.7 RTC clock generation
Table 578. Alarm registers
The RTC includes an alarm output pin that reflects both the alarm comparisons and
interrupts from the RTC. This pin is in the RTC power domain, and therefore it is available
during all power saving modes as long as power is supplied to VBAT. Since the alarm pin
combines the alarm and interrupt functions of the RTC, either a specific time/date/etc. or a
periodic interval can be provided to the outside world. For example, a time-of-day alarm
could be used to tell external circuitry to turn on power to the LPC2400 in order to wake up
from Deep power-down mode.
The RTC may be clocked by either the 32.786 kHz RTC oscillator, or by the APB
peripheral clock (PCLK) after adjustment by the reference clock divider.
The reference clock divider (hereafter referred to as the Prescaler) may be used when the
RTC clock source is not supplied by the RTC oscillator, but comes from the APB
peripheral clock (PCLK).
The Prescaler allows generation of a 32.768 kHz reference clock from any PCLK
frequency greater than or equal to 65.536 kHz (2 × 32.768 kHz). This permits the RTC to
always run at the proper rate regardless of the peripheral clock rate. Basically, the
Prescaler divides PCLK by a value which contains both an integer portion and a fractional
portion. The result is not a continuous output at a constant frequency, some clock periods
will be one PCLK longer than others. However, the overall result can always be 32,768
counts per second.
The reference clock divider consists of a 13 bit integer counter and a 15 bit fractional
counter. The reasons for these counter sizes are as follows:
Name
ALSEC
ALMIN
ALHOUR
ALDOM
ALDOW
ALDOY
ALMON
ALYEAR
1. For frequencies that are expected to be supported by the LPC2400, a 13 bit integer
2. The remainder value could be as large as 32,767, which requires 15 bits.
counter is required. This can be calculated as 160 MHz divided by 32,768 minus 1
equals 4881 with a remainder of 26,624. Thirteen bits are needed to hold the value
4881, but actually supports frequencies up to 268.4 MHz (32,768 × 8192).
Size
6
6
5
5
3
9
4
12
Description
Alarm value for Seconds
Alarm value for Minutes
Alarm value for Hours
Alarm value for Day of Month
Alarm value for Day of Week
Alarm value for Day of Year
Alarm value for Months
Alarm value for Years
Rev. 04 — 26 August 2009
Chapter 26: LPC24XX Real-Time Clock (RTC) and battery RAM
Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
UM10237
© NXP B.V. 2009. All rights reserved.
0xE002 4060
0xE002 4064
0xE002 4068
0xE002 406C
0xE002 4070
0xE002 4074
0xE002 4078
Address
0xE002 407C
656 of 792