MSP430X33X Datasheet, PDF (9/27 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLERS

MSP430x33x
MIXED SIGNAL MICROCONTROLLERS
module enable registers 1 and 2 (continued)
Legend rw:
rw-0:
Bit can be read and written
Bit can be read and written. It is reset by PUC
SFR bit not present in device
SLAS163 – FEBRUARY 1998
ROM memory organization
MSP430C336
FFFFh
FFE0h
FFDFh
Int. Vector
24 kB ROM
A000h
MSP430C337
FFFFh
FFE0h
FFDFh
Int. Vector
32 kB ROM
8000h
FFFFh
FFE0h
FFDFh
MSP430P337
PMS430E337
Int. Vector
32 kB OTP
or
EPROM
8000h
05FFh
0200h
01FFh
0100h
00FFh
0010h
000Fh
0000h
1024B RAM
16b Per.
8b Per.
SFR
05FFh
0200h
01FFh
0100h
00FFh
0010h
000Fh
0000h
1024B RAM
16b Per.
8b Per.
SFR
05FFh
0200h
01FFh
0100h
00FFh
0010h
000Fh
0000h
1024B RAM
16b Per.
8b Per.
SFR
peripherals
Peripherals are connected to the CPU through a data, address, and control bus and can be handled easily with
instructions for memory manipulation.
oscillator and system clock
Two clocks are used in the system, the system (master) clock (MCLK) and the auxiliary clock (ACLK). The MCLK
is a multiple of the ACLK. The ACLK runs with the crystal oscillator frequency. The special design of the oscillator
supports the feature of low current consumption and the use of a 32 768 Hz crystal. The crystal is connected
across two terminals without any other external components being required.
The oscillator starts after applying VCC, due to a reset of the control bit (OscOff) in the status register (SR). It
can be stopped by setting the OscOff bit to a 1. The enabled clock signals ACLK, ACLK/2, ACLK/4, OR MCLK
are accessible for use by external devices at output terminal XBUF .
The controller system clocks have to deal with different requirements according to the application and system
condition. Requirements include:
D High frequency in order to react quickly to system hardware requests or events
D Low frequency in order to minimize current consumption, EMI, etc.
D Stable frequency for timer applications e.g. real time clock (RTC)
D Enable start-stop operation with minimum delay to operation function.
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