UT.6.01

UT.6.01x

Az UT.6.01x egy online kurzus, ami a Tiva C lauchpad-ről és a beágyazott rendszerekről szól.
A kurzust Jonathan Valvano és Ramesh Yerraballi tartja.
Ezen az oldalon a kurzusból idézett szöveg kiemelések, táblázatok és képek vannak, ezeket használom jegyzetnek.

C1 Bevezetés

Folyamatosan gyűjtöm az anyagokat és fordítom, ahogy lehet

C2 Alap fogalmak

Hexadecimális számok

Hex Digit	Decimal  Value	Binary Value
0	0	0000
1	1	0001
2	2	0010
3	3	0011
4	4	0100
5	5	0101
6	6	0110
7	7	0111
8	8	1000
9	9	1001
A or a	10	1010
B or b	11	1011
C or c	12	1100
D or d	13	1101
E or e	14	1110
F or f	15	1111

Beágyazott rendszerek

Processzor típusok: x86 (ált. asztali gép), ARM.
"Az I/O az a ragasztó, amivel a processzor kapcsolódik a világhoz."

Tervezési szempontok: tesztelhetőség, haszon, energia igény, méret, megfelelő válasz megfelelő időben.

Human-computer interface (HCI) or man-machine interface (MMI).
Tipikus példa: multiméter.

Bevezetés a számítógépekhez

Neumann architecture

Számítógép = proceszor + RAM + ROM + IO.
Neumann architecture, "A port is a physical connection between the computer and its outside world. Ports allow information to enter and exit the system."
"A bus is a collection of wires used to pass information between modules."

A busz vezetékek gyűjteménye, amit a modulok közti információ cserére használunk.

Harvard architecture

ARM®Cortex™-M processor. "separate data and instruction buses"

Külön adat, és utasítás buszok.

"The nested vectored interrupt controller (NVIC) manages interrupts, which are hardware-triggered software functions. " A beágyazott irányítható megszakítás-vezérlő - NVIC

---

Fogalmak

A microprocessor is a small processor.

A microcomputer is a small computer that includes a processor, memory and I/O devices.

A microcontroller is a single chip computer.

---

RAM-ROM memory

RAM (random access memory)

ROM (read only memory)
ROM-ok:

Static RAM (SRAM)

Programmable ROM (PROM) 10000 times slower RAM

Electrically erasable programmable ROM (EEPROM)

"In regular EEPROM, you can erase and program individual bytes. "

FLASH ROM

"Flash ROM is a popular type of EEPROM. Each flash bit requires only two MOSFET transistors. The input (gate) of one transistor is electrically isolated, so if we trap charge on this input, it will remain there for years."

"Each flash bit requires only two MOSFET transistors The input (gate) of one transistor is electrically isolated, so if we trap charge on this input, it will remain there for years. The other transistor is used to read the bit by sensing whether or not the other transistor has trapped charge."

"Flash ROM must be erased in large blocks. On many of Stellaris family of microcontrollers, we can erase the entire ROM or just a 1024-byte block."

"Because flash is smaller than regular EEPROM, most microcontrollers have a large flash into which we store the software. For all the systems in this class, we will store instructions and constants in flash ROM and place variables and temporary data in static RAM."

"Flash ROM is higher density because it requires few transistors compared to RAM."

CPU regiszterek

Memory Map Layout

Part number	RAM	Flash	I/O	I/O modules
LM3S811	8	64	32	PWM
LM3S1968	64	256	52	PWM
LM3S2965	64	256	56	PWM, CAN
LM3S3748	64	128	61	PWM, DMA, USB
LM3S6965	64	256	42	PWM, Ethernet
LM3S8962	64	256	42	PWM, CAN, Ethernet, IEEE1588
LM4F110B2QR	12	32	43	floating point, CAN, DMA
LM4F120H5QR	32	256	43	floating point, CAN, DMA, USB
TM4C123GH6PM	32	256	43	floating point, CAN, DMA, USB, PWM
	KiB	KiB	pins

ISA Instruction set architecture

Software

CortexM_InstructionSet.pdf Instruction Set Reference Manual https://courses.edx.org/c4x/UTAustinX/UT.6.01x/asset/CortexM_InstructionSet.pdf

CortexM4_TRM_r0p1.pdf Cortex-M4 Technical Reference Manual https://courses.edx.org/c4x/UTAustinX/UT.6.01x/asset/CortexM_InstructionSet.pdf

LaunchPadUsersManual.pdf LaunchPad Manual

tm4c123gh6pm.pdf Data Sheet for the TM4C123 microcontroller

C3 Elektronikai alapismeretek

Ohm törvény

R = V / I

I = V / R

R = V / I

P = V * I   Power = Voltage  * Current

P = V2 / R  Power = Voltage2 / Resistance           

P = I2 * R  Power = Current2 * Resistance

Energia

Elemekre:

E (energia)= V (feszültség) * I (áramerősség) * time (idő)

E-> állandó ; V -> állandó, az idő vagy az I csökkentésével csökkenthetjük a felhasznált energiát.

C4 Digitális logikai műveletek

D Logikai műveletek

A	B	AND	NAND	OR	NOR	EOR	Ex NOR
0	0	0	1	0	1	0	1
0	1	0	1	1	0	1	0
1	0	0	1	1	0	1	0
1	1	1	0	1	0	0	1
Symbol		A&B	~(A&B)	A|B	~(A|B)	A^B	~(A^B)

Boolean Algebra

A & B = B & A A | B = B | A (A & B) & C = A & (B & C) (A | B) | C = A | (B | C) (A | B) & C = (A & C) | (B & C) (A & B) | C = (A | C) & (B | C) A & 0 = 0 A | 0 = A A & 1 = A A | 1 = 1 A | A = A A | (~A) = 1 A & A = A A & (~A) = 0 ~(~A) = A ~(A | B) = (~A) & (~B) ~(A & B) = (~A) | (~B)

Commutative Law Commutative Law Associative Law Associative Law Distributive Law Distributive Law Identity of 0 Identity of 0 Identity of 1 Identity of 1 Property of OR Property of OR Property of AND Property of AND Inverse De Morgan’s Theorem De Morgan’s Theorem

Large numbers reference

Value	SI          Decimal	SI          Decimal		Value	IEC          Binary	IEC          Binary
10001	k	kilo-		10241	Ki	kibi-
10002	M	mega-		10242	Mi	mebi-
10003	G	giga-		10243	Gi	gibi-
10004	T	tera-		10244	Ti	tebi-
10005	P	peta-		10245	Pi	pebi-
10006	E	exa-		10246	Ei	exbi-
10007	Z	zetta-		10247	Zi	zebi-
10008	Y	yotta-		10248	Yi	yobi-

C4 Beveztés a C-be

Háttér

A C nagyon népszerű nyelv (2013-ban a programok 18%), több programot írnak C-ben mint Javaban, PHP-ben, Python-ban vagy Perl-ben.
Szintén nagyon népszerű még Objective-C és a C++ is.

A C nagyon vas közeli, a beágyazott rendszerek pedig az I/O-kra (GPIO-kra) épülnek.

A C felépítése

Punctuation	Meaning
;	End of statement
:	Defines a label
,	Separates elements of a list
( )	Start and end of a parameter list
{ }	Start and stop of a compound statement
[ ]	Start and stop of a array index
" "	Start and stop of a string
' '	Start and stop of a character constant

Változók (variables)

Data type	Precision	Range
unsigned char	8-bit unsigned	0 to +255
signed char	8-bit signed	-128 to +127
unsigned int	compiler-dependent
int	compiler-dependent
unsigned short	16-bit unsigned	0 to +65535
short	16-bit signed	-32768 to +32767
unsigned long	unsigned 32-bit	0 to 4294967295L
long	signed 32-bit	-2147483648L to 2147483647L
float	32-bit float	±10-38 to ±10+38
double	64-bit float	±10-308 to ±10+308

Műveletek, operátorok

Operation	Meaning		Operation	Meaning
=	Assignment statement		==	Equal to comparison
?	Selection		<=	Less than or equal to
<	Less than		>=	Greater than or equal to
>	Greater than		!=	Not equal to
!	Logical not (true to false, false to true)		<<	Shift left
~	1’s complement		>>	Shift right
+	Addition		++	Increment
-	Subtraction		--	Decrement
*	Multiply or pointer reference		&&	Boolean and
/	Divide		||	Boolean or
%	Modulo, division remainder		+=	Add value to
|	Logical or		-=	Subtract value to
&	Logical and, or address of		*=	Multiply value to
^	Logical exclusive or		/=	Divide value to
.	Used to access parts of a structure		|=	Or value to
			&=	And value to
			^=	Exclusive or value to
			<<=	Shift value left
			>>=	Shift value right
			%=	Modulo divide value to
			->	Pointer to a structure

Precedence	Operators	Associativity
Highest	() []. ->  ++(postfix)  --(postfix)	Left to right
	++(prefix)  --(prefix)   !  ~ sizeof(type) +(unary)  -(unary)  &(address)  *(dereference)	Right to left
	*   /   %	Left to right
	+   -	Left to right
	<<   >>	Left to right
	<    <=   >   >=	Left to right
	==  !=	Left to right
	&	Left to right
	^	Left to right
	|	Left to right
	&&	Left to right
	||	Left to right
	? :	Right to left
	=   +=   -=  *=  /=  %=  <<=  >>=  |=  &=  ^=	Right to left
Lowest	,	Left to right

Kulcsszavak

Keyword	Meaning
__asm	Specify a function is written in assembly code (specific to ARM Keil™ uVision®)
auto	Specifies a variable as automatic (created on the stack)
break	Causes the program control structure to finish
case	One possibility within a switch statement
char	Defines a number with a precision of 8 bits
const	Defines parameter as constant in ROM, and defines a local parameter as fixed value
continue	Causes the program to go to beginning of loop
default	Used in switch statement for all other cases
do	Used for creating program loops
double	Specifies variable as double precision floating point
else	Alternative part of a conditional
extern	Defined in another module
float	Specifies variable as single precision floating point
for	Used for creating program loops
goto	Causes program to jump to specified location
if	Conditional control structure
int	Defines a number with a precision that will vary from compiler to compiler
long	Defines a number with a precision of 32 bits
register	Specifies how to implement a local
return	Leave function
short	Defines a number with a precision of 16 bits
signed	Specifies variable as signed (default)
sizeof	Built-in function returns the size of an object
static	Stored permanently in memory, accessed locally
struct	Used for creating data structures
switch	Complex conditional control structure
typedef	Used to create new data types
unsigned	Always greater than or equal to zero
void	Used in parameter list to mean no parameter
volatile	Can change implicitly outside the direct action of the software.
while	Used for creating program loops

C6 Prortok

I/O Signals

UART Universal asynchronous receiver/transmitter
SSI Synchronous serial interface
I2C Inter-integrated circuit
Timer Periodic interrupts, input capture, and output compare
PWM Pulse width modulation
ADC Analog to digital converter, measure analog signals
Analog Comparator Compare two analog signals
QEI Quadrature encoder interface
USB Universal serial bus
Ethernet  High-speed network
CAN Controller area network
JTAG Joint Test Action Group

"Common Error: Even though it is possible to use the five JTAG pins as general I/O, debugging most microcontroller boards will be more stable if these five pins are left dedicated to the JTAG debugger."

A JTAG tüskéket soha nem szabad általános I/O -ként használni, mert ezeken történik a debugg.

I/O Pins

IO

Ain

0

1

2

3

4

5

6

7

8

9

14

PA0

Port

U0Rx

CAN1Rx

PA1

Port

U0Tx

CAN1Tx

PA2

Port

SSI0Clk

PA3

Port

SSI0Fss

PA4

Port

SSI0Rx

PA5

Port

SSI0Tx

PA6

Port

I2C1SCL

M1PWM2

PA7

Port

I2C1SDA

M1PWM3

PB0

Port

U1Rx

T2CCP0

PB1

Port

U1Tx

T2CCP1

PB2

Port

I2C0SCL

T3CCP0

PB3

Port

I2C0SDA

T3CCP1

PB4

Ain10

Port

SSI2Clk

M0PWM2

T1CCP0

CAN0Rx

PB5

Ain11

Port

SSI2Fss

M0PWM3

T1CCP1

CAN0Tx

PB6

Port

SSI2Rx

M0PWM0

T0CCP0

PB7

Port

SSI2Tx

M0PWM1

T0CCP1

PC4

C1-

Port

U4Rx

U1Rx

M0PWM6

IDX1

WT0CCP0

U1RTS

PC5

C1+

Port

U4Tx

U1Tx

M0PWM7

PhA1

WT0CCP1

U1CTS

PC6

C0+

Port

U3Rx

PhB1

WT1CCP0

USB0epen

PC7

C0-

Port

U3Tx

WT1CCP1

USB0pflt

PD0

Ain7

Port

SSI3Clk

SSI1Clk

I2C3SCL

M0PWM6

M1PWM0

WT2CCP0

PD1

Ain6

Port

SSI3Fss

SSI1Fss

I2C3SDA

M0PWM7

M1PWM1

WT2CCP1

PD2

Ain5

Port

SSI3Rx

SSI1Rx

M0Fault0

WT3CCP0

USB0epen

PD3

Ain4

Port

SSI3Tx

SSI1Tx

IDX0

WT3CCP1

USB0pflt

PD4

USB0DM

Port

U6Rx

WT4CCP0

PD5

USB0DP

Port

U6Tx

WT4CCP1

PD6

Port

U2Rx

M0Fault0

PhA0

WT5CCP0

PD7

Port

U2Tx

PhB0

WT5CCP1

NMI

PE0

Ain3

Port

U7Rx

PE1

Ain2

Port

U7Tx

PE2

Ain1

Port

PE3

Ain0

Port

PE4

Ain9

Port

U5Rx

I2C2SCL

M0PWM4

M1PWM2

CAN0Rx

PE5

Ain8

Port

U5Tx

I2C2SDA

M0PWM5

M1PWM3

CAN0Tx

PF0

Port

U1RTS

SSI1Rx

CAN0Rx

M1PWM4

PhA0

T0CCP0

NMI

C0o

PF1

Port

U1CTS

SSI1Tx

M1PWM5

PhB0

T0CCP1

C1o

TRD1

PF2

Port

SSI1Clk

M0Fault0

M1PWM6

T1CCP0

TRD0

PF3

Port

SSI1Fss

CAN0Tx

M1PWM7

T1CCP1

TRCLK

PF4

Port

M1Fault0

IDX0

T2CCP0

USB0epen

I/O Registers

"A DIR bit of 0 means input and 1 means output."

"Common Error: You will get a bus fault if you access a port without enabling its clock."

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• DIR 0 means input and 1 means output
• PCTL select regular digital function.
• LOCK unlock the port; Only PC3-0, PD7, and PF0 on the TM4C need to be unlocked
• AMSEL analog functionality
• AFSEL alternative function
• PUR internal pull-up resistor

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Registers

Address	7	6	5	4	3	2	1	0	Name
$400F.E108	--	--	GPIOF	GPIOE	GPIOD	GPIOC	GPIOB	GPIOA	SYSCTL_RCGC2_R
$4000.43FC	DATA	DATA	DATA	DATA	DATA	DATA	DATA	DATA	GPIO_PORTA_DATA_R
$4000.4400	DIR	DIR	DIR	DIR	DIR	DIR	DIR	DIR	GPIO_PORTA_DIR_R
$4000.4420	SEL	SEL	SEL	SEL	SEL	SEL	SEL	SEL	GPIO_PORTA_AFSEL_R
$4000.4510	PUE	PUE	PUE	PUE	PUE	PUE	PUE	PUE	GPIO_PORTA_PUR_R
$4000.451C	DEN	DEN	DEN	DEN	DEN	DEN	DEN	DEN	GPIO_PORTA_DEN_R
$4000.4524	1	1	1	1	1	1	1	1	GPIO_PORTA_CR_R
$4000.4528	0	0	0	0	0	0	0	0	GPIO_PORTA_AMSEL_R
$4000.53FC	DATA	DATA	DATA	DATA	DATA	DATA	DATA	DATA	GPIO_PORTB_DATA_R
$4000.5400	DIR	DIR	DIR	DIR	DIR	DIR	DIR	DIR	GPIO_PORTB_DIR_R
$4000.5420	SEL	SEL	SEL	SEL	SEL	SEL	SEL	SEL	GPIO_PORTB_AFSEL_R
$4000.5510	PUE	PUE	PUE	PUE	PUE	PUE	PUE	PUE	GPIO_PORTB_PUR_R
$4000.551C	DEN	DEN	DEN	DEN	DEN	DEN	DEN	DEN	GPIO_PORTB_DEN_R
$4000.5524	1	1	1	1	1	1	1	1	GPIO_PORTB_CR_R
$4000.5528	0	0	AMSEL	AMSEL	0	0	0	0	GPIO_PORTB_AMSEL_R
$4000.63FC	DATA	DATA	DATA	DATA	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_DATA_R
$4000.6400	DIR	DIR	DIR	DIR	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_DIR_R
$4000.6420	SEL	SEL	SEL	SEL	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_AFSEL_R
$4000.6510	PUE	PUE	PUE	PUE	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_PUR_R
$4000.651C	DEN	DEN	DEN	DEN	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_DEN_R
$4000.6524	1	1	1	1	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_CR_R
$4000.6528	AMSEL	AMSEL	AMSEL	AMSEL	JTAG	JTAG	JTAG	JTAG	GPIO_PORTC_AMSEL_R
$4000.73FC	DATA	DATA	DATA	DATA	DATA	DATA	DATA	DATA	GPIO_PORTD_DATA_R
$4000.7400	DIR	DIR	DIR	DIR	DIR	DIR	DIR	DIR	GPIO_PORTD_DIR_R
$4000.7420	SEL	SEL	SEL	SEL	SEL	SEL	SEL	SEL	GPIO_PORTD_AFSEL_R
$4000.7510	PUE	PUE	PUE	PUE	PUE	PUE	PUE	PUE	GPIO_PORTD_PUR_R
$4000.751C	DEN	DEN	DEN	DEN	DEN	DEN	DEN	DEN	GPIO_PORTD_DEN_R
$4000.7524	CR	1	1	1	1	1	1	1	GPIO_PORTD_CR_R
$4000.7528	0	0	AMSEL	AMSEL	AMSEL	AMSEL	AMSEL	AMSEL	GPIO_PORTD_AMSEL_R
$4002.43FC			DATA	DATA	DATA	DATA	DATA	DATA	GPIO_PORTE_DATA_R
$4002.4400			DIR	DIR	DIR	DIR	DIR	DIR	GPIO_PORTE_DIR_R
$4002.4420			SEL	SEL	SEL	SEL	SEL	SEL	GPIO_PORTE_AFSEL_R
$4002.4510			PUE	PUE	PUE	PUE	PUE	PUE	GPIO_PORTE_PUR_R
$4002.451C			DEN	DEN	DEN	DEN	DEN	DEN	GPIO_PORTE_DEN_R
$4002.4524			1	1	1	1	1	1	GPIO_PORTE_CR_R
$4002.4528			AMSEL	AMSEL	AMSEL	AMSEL	AMSEL	AMSEL	GPIO_PORTE_AMSEL_R
$4002.53FC				DATA	DATA	DATA	DATA	DATA	GPIO_PORTF_DATA_R
$4002.5400				DIR	DIR	DIR	DIR	DIR	GPIO_PORTF_DIR_R
$4002.5420				SEL	SEL	SEL	SEL	SEL	GPIO_PORTF_AFSEL_R
$4002.5510				PUE	PUE	PUE	PUE	PUE	GPIO_PORTF_PUR_R
$4002.551C				DEN	DEN	DEN	DEN	DEN	GPIO_PORTF_DEN_R
$4002.5524				1	1	1	1	CR	GPIO_PORTF_CR_R
$4002.5528				0	0	0	0	0	GPIO_PORTF_AMSEL_R
	31-28	27-24	23-20	19-16	15-12	11-8	7-4	3-0
$4000.452C	PMC7	PMC6	PMC5	PMC4	PMC3	PMC2	PMC1	PMC0	GPIO_PORTA_PCTL_R
$4000.552C	PMC7	PMC6	PMC5	PMC4	PMC3	PMC2	PMC1	PMC0	GPIO_PORTB_PCTL_R
$4000.652C	PMC7	PMC6	PMC5	PMC4	0x1	0x1	0x1	0x1	GPIO_PORTC_PCTL_R
$4000.752C	PMC7	PMC6	PMC5	PMC4	PMC3	PMC2	PMC1	PMC0	GPIO_PORTD_PCTL_R
$4002.452C			PMC5	PMC4	PMC3	PMC2	PMC1	PMC0	GPIO_PORTE_PCTL_R
$4002.552C				PMC4	PMC3	PMC2	PMC1	PMC0	GPIO_PORTF_PCTL_R
$4000.6520	LOCK (write 0x4C4F434B to unlock, other locks) (reads 1 if locked, 0 if unlocked)								GPIO_PORTC_LOCK_R
$4000.7520	LOCK (write 0x4C4F434B to unlock, other locks) (reads 1 if locked, 0 if unlocked)								GPIO_PORTD_LOCK_R
$4002.5520	LOCK (write 0x4C4F434B to unlock, other locks) (reads 1 if locked, 0 if unlocked)								GPIO_PORTF_LOCK_R

Regiszter programozás

Maszkolás writing friendly code

* OR művelettel egy bitet BE kapcsolhatunk; ahova 1-et írunk 1 lesz; ahova 0-t ott nem változik
* AND művelettel egy bitet LE kapcsolhatunk; ahova 0-t írunk 0 lesz; ahova 1-t ott nem változik

* Egyszerűbb annak a bitnek amit le akarunk kapcsolni, az ellentettjét (~) maszkolni AND művelettel. (&)

* Ha le akarok olvasni egy bitet egy regiszterből, & -em a bit helyét.

Gyakori maszkolási értékek

If we wish to access bit	Constant
7	0x0200
6	0x0100
5	0x0080
4	0x0040
3	0x0020
2	0x0010
1	0x0008
0	0x0004

Port címzések

Port	Base address
PortA	0x40004000
PortB	0x40005000
PortC	0x40006000
PortD	0x40007000
PortE	0x400240000
PortF	0x40025000

C7 Tervezési és fejlesztési folyamat

Termék életciklusai

• Probléma meghatározása
• Tervezés
• Fejlesztés
• Tesztelés
• Üzembe helyezés

Tervezési kritériumok

• Safety: The risk to humans or the environment
  
• Accuracy: The difference between the expected truth and the actual parameter
  
• Precision: The number of distinguishable measurements
  
• Resolution: The smallest change that can be reliably detected
  
• Response time: The time between a triggering event and the resulting action
  
• Bandwidth: The amount of information processed per time
  
• Maintainability: The flexibility with which the device can be modified
  
• Testability: The ease with which proper operation of the device can be verified
  
• Compatibility: The conformance of the device to existing standards
  
• Mean time between failure: The reliability of the device, the life of a product
  
• Size and weight: The physical space required by the system
  
• Power: The amount of energy it takes to operate the system
  
• Nonrecurring engineering cost (NRE cost): The one-time cost to design and test
  
• Unit cost: The cost required to manufacture one additional product
  
• Time-to-prototype: The time required to design, build, and test an example system
  
• Time-to-market: The time required to deliver the product to the customer
  
• Human factors: The degree to which our customers like/appreciate the product
  

Tippek

"Common Error: Programmers who sacrifice clarity in favor of execution speed often develop software that runs fast, but is error-prone and difficult to change."

"Observation: The easiest way to debug is to write software without any bugs."

"Maintenance Tip: Go from working system to working system."

"Maintenance Tip: It is better to have some parts of the system that run with 100% reliability than to have the entire system with bugs."

"Maintenance Tip: It is better to have a system that runs slowly than to have one that doesn’t run at all."

"Observation:There are two ways of constructing a software design: one way is to make it so simple that there are obviously no deficiencies and the other way is make it so complicated that there are no obvious deficiencies. C.A.R. Hoare, "The Emperor's Old Clothes," CACM Feb. 1981."

Azaz kétféle képen tervezhetünk egy szoftvert:
"Az egyik út hogy annyira egyszerű hogy nyilvánvalóan nincs benne hiba
A másik lehetőség az, hogy olyan bonyolult hogy nincsenek egyértelmű hibák."

Funkciók, eljárások, módszerek, szubrutinok

Ezek kialakítására a a hiba megelőzést segíti.

• "Make the software project easier to understand"
• "Increase the number of modules"
• "Decrease the interdependency (minimize bandwidth between modules)."

Fontos hogy ne keverjük a különböző változókat!

C8 Switches and leds

Leds

Előtét ellenállás számítás:

• Positive logic: R = VOH-Vd / Id
• Negative logic: R = 3.3-Vd-VOL / Id

Positive logic:	Negative logic:

UTx.6.01 course

C9 Arrays & functional debugging

Debugging Theory

* Black-box testing: "is simply observing the inputs and outputs without looking inside."
* White-box testing: "allows you to control and observe the internal workings of a system."

Common Error: "The most common debugging mistake new programmers make is to simply observe the overall inputs and outputs system without looking inside the device. Then they go to their professor and say, “My program gives incorrect output. Do you know why?”

SysTick timer

(nem telje, a systick órajel beállítása itt)

Address	31-24	23-17	16	15-3	2	1	0	Name
$E000E010	0	0	COUNT	0	CLK_SRC	INTEN	ENABLE	NVIC_ST_CTRL_R
$E000E014	0	24-bit RELOAD value						NVIC_ST_RELOAD_R
$E000E018	0	24-bit CURRENT value of SysTick counter						NVIC_ST_CURRENT_R

Inicializálás

#define NVIC_ST_CTRL_R      (*((volatile unsigned long *)0xE000E010))
#define NVIC_ST_RELOAD_R    (*((volatile unsigned long *)0xE000E014))
#define NVIC_ST_CURRENT_R   (*((volatile unsigned long *)0xE000E018))
void SysTick_Init(void){
  NVIC_ST_CTRL_R = 0;              // 1) disable SysTick during setup
  NVIC_ST_RELOAD_R = 0x00FFFFFF;   // 2) maximum reload value
  NVIC_ST_CURRENT_R = 0;           // 3) any write to current clears it
  NVIC_ST_CTRL_R = 0x00000005;     // 4) enable SysTick with core clock
}

Example

unsigned long Now;      // 24-bit time at this call (12.5ns)
unsigned long Last;     // 24-bit time at previous call (12.5ns)
unsigned long Elapsed;  // 24-bit time between calls (12.5ns)
void Action(void){      // function under test
 Now = NVIC_ST_CURRENT_R;         // what time is it now?
 Elapsed = (Last-Now)&0x00FFFFFF; // 24-bit difference
 Last = Now;                      // set up for next...
}

String

A String egy karakter sorozat, maga szöveg.

Mindig 0-ra végződik, de ezt nem kell írni, fordításnál alapértelmezetten bekerül.

Speciális karakterk:

Character	Escape Sequence
alert (beep)	\a
backslash	\\
backspace	\b
carriage return	\r
double quote	\"
form feed	\f
horizontal tab	\t
newline	\n
null character	\0
single quote	\'
vertical tab	\v
question mark	\?

C10 Finite State Machine

Phase-Lock-Loop PLL

"internal oscillator is 16 MHz ±1%"

A LM4F/TM4C MCU-kban van egy belső oszcillátor ez 16 MHz ±1%. Az egy 1% nagyon nagy hibahatár, ezért kell egy külső kristály ami pontosabb.
A Tiva C launchpaden egy 16 MHz-es NX5032GA ±50 parts per million (PPM) kristály van. Az ±50 PPM 0.005% hibahatárt jelent "which is about ±5 seconds per day"

Más kristályt is használhatunk, az értékének megfelelően be kell állítani az SysTick XTAL regiszterét az alábbiak szerint:

'''XTAL'''	Crystal Freq (MHz)		'''XTAL'''	Crystal Freq (MHz)
0x0	Reserved		0x10	10.0 MHz
0x1	Reserved		0x11	12.0 MHz
0x2	Reserved		0x12	12.288 MHz
0x3	Reserved		0x13	13.56 MHz
0x4	3.579545 MHz		0x14	14.31818 MHz
0x5	3.6864 MHz		0x15	16.0 MHz
0x6	4 MHz		0x16	16.384 MHz
0x7	4.096 MHz		0x17	18.0 MHz
0x8	4.9152 MHz		0x18	20.0 MHz
0x9	5 MHz		0x19	24.0 MHz
0xA	5.12 MHz		0x1A	25.0 MHz
0xB	6 MHz (reset value)		0x1B	Reserved
0xC	6.144 MHz		0x1C	Reserved
0xD	7.3728 MHz		0x1D	Reserved
0xE	8 MHz		0x1E	Reserved
0xF	8.192 MHz		0x1F	Reserved

SysTick registers

Address	26-23	22	13	11	10-6	5-4	Name
$400FE060	SYSDIV	USESYSDIV	PWRDN	BYPASS	XTAL	OSCSRC	SYSCTL_RCC_R
$400FE050					PLLRIS		SYSCTL_RIS_R
	31	30	28-22	13	11	6-4
$400FE070	USERCC2	DIV400	SYSDIV2	PWRDN2	BYPASS2	OSCSRC2	SYSCTL_RCC2_R

PLL init

void PLL_Init(void){
 // 0) Use RCC2
 SYSCTL_RCC2_R |=  0x80000000;  // USERCC2
 // 1) bypass PLL while initializing
 SYSCTL_RCC2_R |=  0x00000800;  // BYPASS2, PLL bypass
 // 2) select the crystal value and oscillator source
 SYSCTL_RCC_R = (SYSCTL_RCC_R &~0x000007C0)   // clear XTAL field, bits 10-6
                + 0x00000540;   // 10101, configure for 16 MHz crystal
 SYSCTL_RCC2_R &= ~0x00000070;  // configure for main oscillator source
 // 3) activate PLL by clearing PWRDN
 SYSCTL_RCC2_R &= ~0x00002000;
 // 4) set the desired system divider
 SYSCTL_RCC2_R |= 0x40000000;   // use 400 MHz PLL
 SYSCTL_RCC2_R = (SYSCTL_RCC2_R&~ 0x1FC00000)  // clear system clock divider
                 + (4<<22);      // configure for 80 MHz clock
 // 5) wait for the PLL to lock by polling PLLLRIS
 while((SYSCTL_RIS_R&0x00000040)==0){};  // wait for PLLRIS bit
 // 6) enable use of PLL by clearing BYPASS
 SYSCTL_RCC2_R &= ~0x00000800;
}
//Program 10.1. Activate the LM4F/TM4C with a 16 MHz crystal to run at 80 MHz (C10_PLL.zip).

Delays; Useing SysTick

A busz 2 számolása közt, 80MHz-en, 12.5 ns telik el, ennek megfelelően: " The RELOAD register is set to the number of bus cycles one wishes to wait. If the PLL function of Program 10.1 has been executed, then the units of this delay will be 12.5 ns. Writing to CURRENT will clear the counter and will clear the count flag (bit 16) of the CTRL register. After SysTick has been decremented delay times, the count flag will be set and the while loop will terminate. Since SysTick is only 24 bits, the maximum time one can wait with SysTick_Wait is 224*12.5ns, which is about 200 ms. To provide for longer delays, the function SysTick_Wait10ms calls the function SysTick_Wait repeatedly. Notice that 800,000*12.5ns is 10ms."

Bomba biztos Delay-ek

#define NVIC_ST_CTRL_R      (*((volatile unsigned long *)0xE000E010))
#define NVIC_ST_RELOAD_R    (*((volatile unsigned long *)0xE000E014))
#define NVIC_ST_CURRENT_R   (*((volatile unsigned long *)0xE000E018))
 void SysTick_Init(void){
  NVIC_ST_CTRL_R = 0;               // disable SysTick during setup
  NVIC_ST_CTRL_R = 0x00000005;      // enable SysTick with core clock
}
// The delay parameter is in units of the 80 MHz core clock. (12.5 ns)
void SysTick_Wait(unsigned long delay){
  NVIC_ST_RELOAD_R = delay-1;  // number of counts to wait
  NVIC_ST_CURRENT_R = 0;       // any value written to CURRENT clears
  while((NVIC_ST_CTRL_R&0x00010000)==0){ // wait for count flag
  }
}
// 800000*12.5ns equals 10ms
void SysTick_Wait10ms(unsigned long delay){
  unsigned long i;
  for(i=0; i<delay; i++){
    SysTick_Wait(800000);  // wait 10ms
  }
}
//Program 10.2. Use of SysTick to delay for a specified amount of time (C10_SysTick_Wait).

Struktúrák

//Meghatározzuk a strukturat:
struct player{
  unsigned char Xpos;     // first element 
  unsigned char Ypos;     // second element 
  unsigned short Score;   // third element 
};
typedef struct player playerType;

//We can allocate a variable called Sprite of this type, which will occupy four bytes in RAM:
//azaz lefoglaljuk a strukturánknak megfeleo Sprite, valtozoit a RAM-ban
playerType Sprite;

//dolgozhatunk az ertekekkel
  Sprite.Xpos = 10;
  Sprite.Ypos = 20;
  Sprite.Score = 12000;