MSP430F2274-EP_14 Datasheet, PDF (11/81 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLER

MSP430F2274-EP
www.ti.com
SLAS614D – SEPTEMBER 2008 – REVISED MAY 2011
Peripherals
Peripherals are connected to the CPU through data, address, and control busses and can be handled using all
instructions. For complete module descriptions, refer to the MSP430x2xx Family User's Guide.
Oscillator and System Clock
The clock system is supported by the basic clock module that includes support for a 32768-Hz watch crystal
oscillator, an internal very low power, low frequency oscillator and an internal digitally-controlled oscillator (DCO).
The basic clock module is designed to meet the requirements of both low system cost and low-power
consumption. The internal DCO provides a fast turn-on clock source and stabilizes in less than 1 μs. The basic
clock module provides the following clock signals:
• Auxiliary clock (ACLK), sourced either from a 32768-Hz watch crystal or the internal LF oscillator for –55°C to
105°C operation. For > 105°C, use external clock source.
• Main clock (MCLK), the system clock used by the CPU
• Sub-Main clock (SMCLK), the sub-system clock used by the peripheral modules
DCO Calibration Data (provided from factory in flash info memory segment A)
DCO Frequency
Calibration Register
Size
Address
CALBC1_1MHZ
byte
1 MHz
CALDCO_1MHZ
byte
010FFh
010FEh
CALBC1_8MHZ
byte
8 MHz
CALDCO_8MHZ
byte
010FDh
010FCh
CALBC1_12MHZ
byte
12 MHz
CALDCO_12MHZ
byte
010FBh
010FAh
CALBC1_16MHZ
byte
16 MHz
CALDCO_16MHZ
byte
010F9h
010F8h
Brownout
The brownout circuit is implemented to provide the proper internal reset signal to the device during power on and
power off.
Digital I/O
There are four 8-bit I/O ports implemented – ports P1, P2, P3, and P4:
• All individual I/O bits are independently programmable.
• Any combination of input, output, and interrupt condition is possible.
• Edge-selectable interrupt input capability for all the eight bits of port P1 and P2.
• Read/write access to port-control registers is supported by all instructions.
• Each I/O has an individually programmable pullup/pulldown resistor.
WDT+ Watchdog Timer
The primary function of the watchdog timer (WDT+) module is to perform a controlled system restart after a
software problem occurs. If the selected time interval expires, a system reset is generated. If the watchdog
function is not needed in an application, the module can be disabled or configured as an interval timer and can
generate interrupts at selected time intervals.
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