msp430f2121irge Microchip Technology Inc., msp430f2121irge Datasheet - Page 9

• Manufacturer Part Number: msp430f2121irge
• Description: Msp430
• Manufacturer: Microchip Technology Inc.

peripherals
oscillator and system clock
brownout
digital I/O
WDT+ watchdog timer
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.
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
D
D
The brownout circuit is implemented to provide the proper internal reset signal to the device during power on
and power off.
There are two 8-bit I/O ports implemented—ports P1 and P2:
D
D
D
D
D
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.
Auxiliary clock (ACLK), sourced from a 32768-Hz watch crystal or a high frequency crystal.
Main clock (MCLK), the system clock used by the CPU.
Sub-Main clock (SMCLK), the sub-system clock used by the peripheral modules.
All individual I/O bits are independently programmable.
Any combination of input, output, and interrupt conditions 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 pull−up/pull−down resistor.
DCO Frequency
DCO Calibration Data (provided from factory in flash info memory segment A)
12 MHz
12 MHz
16 MHz
16 MHz
1 MHz
1 MHz
8 MHz
8 MHz
POST OFFICE BOX 655303
Calibration Register
CALDCO_12MHZ
CALDCO_16MHZ
CALBC1_12MHZ
CALBC1_16MHZ
CALDCO_1MHZ
CALDCO_8MHZ
CALBC1_1MHZ
CALBC1_8MHZ
•
DALLAS, TEXAS 75265
MIXED SIGNAL MICROCONTROLLER
Size
byte
byte
byte
byte
byte
byte
byte
byte
SLAS439C − SEPTEMBER 2004 − REVISED JULY 2006
Address
010FDh
010FCh
010FFh
010FEh
010FBh
010FAh
010F9h
010F8h
MSP430x21x1
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