A review of MSP430x1xx to use it in microbotics

1. Microcontrollers: The brain of the bot
MSP430
Cristina Urdiales
Departamento de Tecnología Electrónica
Universidad de Málaga
International Summer Workshop on microbotics 2011

2. INTRODUCTION
What is a microcontroller?
MICROPROCESSOR
0
MICROCONTROLLER
International Summer Workshop on microbotics 2011

3. INTRODUCTION
What is a microcontroller?
TRADITIONAL CIRCUIT MICROCONTROLLER
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4. INTRODUCTION
Types of microcontrollers
✔
GENERAL PURPUSE, LOW COST
✔
ULTRALOW POWER CONSUMPTION
✔
AVERAGE PERFORMANCE
Ethernet, VGA, LCD, Touch-screen, etc…
Standard architectures, Limited OS
✔
HIGH PERFORMANCE
Linux, windows CE, …
High graphic performance
As powerful as a few years old PC
✔
DSPs
✔
MIXED ARCHITECTURE
DSP+Microprocessors
✔
FPGAs
Free Hardware
International Summer Workshop on microbotics 2011

5. INTRODUCTION
Ultra low power consumption: Examples
Devices of limited weight
• Device fed with button battery (80 mAH). Average power
consumption: 8 uA => 1,14 years
Devices requiring long term operation:
• Wireless sensor network: required life 8 years. Average power
consumption 200 uA. => Battery required 15.000 mAH.
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6. INTRODUCTION
Ultra low power consumption: Examples
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7. MSP430 TI
114
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8. MSP430 TI
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9. MSP430 TI
MSP430x1xx Features
• Ultra Low Power Consumption
- Feeding range: 1,8 – 3,6 V
- Several ULPC modes
• Core: CPU RISC 16 bits
- High processing performance
- Memory optimization
• High performance periferals: ADCs, TIMERs, USARTs,
comparers, battery level indicators, I2C ...
• Flexible clock system
• JTAG integrated
• Low cost
- Development system around 50€
- Microcontrollers 1-3€
International Summer Workshop on microbotics 2011

10. MSP430 TI
MSP430x1xx Features
➢
Von Neumann architecture
➢
Data and Address buses: 16 bits
➢
Data format .B and .W
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11. MSP430 TI REGISTERS
MSP430x1xx Features
MEMORY MAP
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12. MSP430 TI
MSP430x1xx Features
ADDRESS MODES
MODE REP. DESCRIPTION EXAMPLE Valid for
Register Rn Data contained in Rn MOV R10,R11 OyD
Indexed X(Rn) Data in (Rn+X) MOV 2(R5),6(R6) OYD
Data in (PC+X) (X given by
Symbolic ADDR MOV EDE, TONI OYD
assembler)
Absolute &ADDR Data in address ADDR MOV &EDE, &TONI OYD
Indirect ro Register @Rn Rn points to data MOV @R10,0(R11) O
Indirect and Rn points to data and increases
@Rn+ MOV @R10+,0(R11) O
automatic increase after operation
Inmediate #N Data is N MOV #45H,TONI O
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13. MSP430 TI
MSP430x1xx Features
ADDRESS MODES
TONI
EDE
MOV
&EDE
TONI
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14. MSP430 TI
MSP430x1xx Features
ADDRESS MODES
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15. MSP430 TI
MSP430x1xx Assembler
DIRECTIVES
-#include “namefile”
-Eg. <msp430x1xx.h> and <intrinsics.h> (only C/C++)
-”;”: Comment
- ORG expr; eg. ORG $5000
-label EQU expr; eg. PI EQU 3.14
-DS8 size, DS16 size, DS32 size; eg. DS8 7
-DB val, DW val, DL val; eg. DB 8
-PUBLIC simbol, EXTERN simbol; ej. PUBLIC myvar EXTERN myvar
-END
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16. MSP430 TI
MSP430x1xx Assembler
INSTRUCTIONS
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17. MSP430 TI
MSP430x1xx Assembler
INSTRUCTIONS
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18. MSP430 TI
MSP430x1xx Assembler
INSTRUCTIONS
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19. MSP430 TI
MSP430x1xx Assembler
INSTRUCTIONS (EMULATED)
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20. MSP430 TI
MSP430x1xx Assembler
INSTRUCTIONS (EMULATED)
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21. MSP430 TI
MSP430x1xx Clock System
SIGNALS
SOURCES
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22. MSP430 TI
MSP430x1xx Clock System
LFXT1
• Low Frecuency: XTS=0 and XTL 32768Hz  Ultra low power comsumption
• High Frecuency: XTS=1  enhanced processing speed
• OFF MODE: OSCOFF=1 (LFXT1CLK can't be MCLK or SMCLK)
XT2 (if available)
• Equal to LFXT1 in HF mode
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23. MSP430 TI
MSP430x1xx Clock System
LFXT1
XT2 (if available)
• Equal to LFXT1 in HF mode
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24. MSP430 TI
MSP430x1xx. Módulo de reloj
MSP430x1xx Clock System
DCO
• RC Oscillator  frequency changes with T and V
• OFF MODE SCG0=1 (as long as it is not the source for MCLK o
SMCLK)
• Digital Control 
- Injected current DC  main frequency
 forced by resistor
- DCOR chooses external or inner resistor
- Control Rsel0 – Rsel2 => 8 values
- Bits DCO0-DCO2 => adjust DCOCLK
- Modulation Bits MOD0 – MOD4  stabilization
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25. MSP430 TI
MSP430x1xx. Módulo de reloj
MSP430x1xx Clock System
DCO
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26. MSP430 TI
MSP430x1xx. Módulo de reloj
MSP430x1xx Power Consumption modes
SCG SCG OSCO CPUO
MODE
1 0 FF FF
Active 0 0 0 0
Low Power 0 0 0 0 1
Low Power 1 0 1 0 1
Low Power 2 1 0 0 1
Low Power 3 1 1 0 1
Low Power 4 1 1 1 1
• Bit CPUOFF: (0/1)  MCLK active/stopped
Bit OSCOFF: (0/1)  LFXT1 active/stopped*
Bit SCG0:(0/1)  GENERADOR DC active/stopped*
Bit SCG1:(0/1)  SMCLK active/stopped*
*As long as not used for main clock signalsj.
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27. MSP430x1xx InterruptionsMSP430 TI
MSP430x1xx. Módulo de reloj
1. (depending on CPU state): Finish current instruction/exit LPC
2. Store PC in pile
3. Store SR in pile
4. Choose highest priority interruption
5. Reset interruption flag (if pertaining)
6. GIE=CPUOFF=SCG1=V=N=Z=C=0
7. Load interruption vector content on PC
Recover after RETI
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28. MSP430 TI
MSP430x1xx. Módulo de reloj
MSP430x1xx Interruptions
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