MSP430F2101 Datasheet, PDF (9/53 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLER

MSP430x21x1
MIXED SIGNAL MICROCONTROLLER
SLAS439C − SEPTEMBER 2004 − REVISED JULY 2006
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 digitally-controlled oscillator (DCO) and a high frequency crystal oscillator. 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:
D Auxiliary clock (ACLK), sourced from a 32768-Hz watch crystal or a high frequency crystal.
D Main clock (MCLK), the system clock used by the CPU.
D 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
1 MHz
CALBC1_1MHZ
byte
010FFh
CALDCO_1MHZ
byte
010FEh
8 MHz
CALBC1_8MHZ
byte
010FDh
CALDCO_8MHZ
byte
010FCh
12 MHz
CALBC1_12MHZ
byte
010FBh
CALDCO_12MHZ
byte
010FAh
16 MHz
CALBC1_16MHZ
byte
010F9h
CALDCO_16MHZ
byte
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 two 8-bit I/O ports implemented—ports P1 and P2:
D All individual I/O bits are independently programmable.
D Any combination of input, output, and interrupt conditions is possible.
D Edge-selectable interrupt input capability for all the eight bits of port P1 and P2.
D Read/write access to port-control registers is supported by all instructions.
D Each I/O has an individually programmable pull−up/pull−down 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 configured as an interval timer and can generate
interrupts at selected time intervals.
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