Embedded system development and labs for ARM (R. Muresan, 2005)

Embedded Systems Development and Labs; The English Edition

Have the 44init.s window active and compile the file by clicking on the Build >> Compile 44init.s. After this build the project and reconnect and download the code to the board. Make sure that the ..\common\ev40boot.cs file is present in the debug window of the project settings.

4)Open Memory1 window, key in the address 0x0C010000. Open Memory2 window, key in the address 0x0C010200.

5)Open Rwrams.s, set a break point at the line “LDR r2, =0x0C010000”. Open Rwarmc.c, set a break point at the line “*ptr=0xAA55AA55;”.

6)Execute the program. The program will stop at the line “LDR r2, =0x0C010000”. Watch the date content in the Memory1 window. Single step execute the program and watch the changes in Memory 1 window. According to the program, master the method of visiting memory using assembly language.

7)When the program stops at the line “*ptr=0xAA55AA55;”, watch the content in the Memory2 window. Single step execute the program and watch the changes in Memory2 window. According to the program, master the method of visiting memory using C language.

8)After understanding and mastering the lab, finish the Lab exercises.

4.4.6 Sample Programs

44binit.s, 44blib.c: these source files can be found in the …\Samsung\S3CEV40\Common directory.

RWrams.s source code:

//////////// RAM read/write using assembly language sRWramtest:

LDR

LDR

STR

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Embedded Systems Development and Labs; The English Edition

RWramc.c source code:

//////////// RAM read/write using C language

#define RWram (*(unsigned long *)0x0c010200) void cRWramtest(void)

{

unsigned long * ptr = 0x0c010200;//RWram; unsigned short * ptrh = 0x0c010200;//RWram; unsigned char * ptrb = 0x0c010200;//RWram;

char i;

unsigned char tmpb; unsigned short tmph; unsigned long tmpw;

*ptr = 0xAA55AA55;

}

main.c source code: #define RWNum 100

#define RWBase 0x0c030000 /*--- function declare ---*/ void Test_MEM(void);

void main(void);

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/*--- extern function ---*/ extern void sRWramtest(void);

/****************************************

*modify:

*comment:

************************************************/

void main(void)

{

Test_MEM();

Uart_Printf("\n Press any key to exit Memory Test.\n");

Uart_Getch();

__asm("mov pc,#0"); // return;

}

void Test_MEM(void)

{

int i,step;

volatile char input_char;

Uart_Printf(

"\n ================= Memory Read/Write Access Test. ================= \n");

Uart_Printf("\n Memory Read/Write(ASM code) Test. \n"); sRWramtest();

Uart_Printf("\n Press any key to continue... \n"); Uart_Getch();

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Embedded Systems Development and Labs; The English Edition

Uart_Printf(" Memory Read/Write(C code =>Word) Test. \n");

Uart_Printf(" Base Address is: %x\n",RWBase);

Uart_Printf(" Memory Units is: %x\n",RWNum);

Uart_Printf(" Access Memory Times is: %d\n",i);

Uart_Printf("\n Press any key to continue... \n");

Uart_Getch();

(*(short *)(RWBase +i*step)) = 0xFF00;

(*(short *)(RWBase +RWNum+i*step)) = (*(short *)(RWBase +i*step));

}

Uart_Printf(" Memory Read/Write(C code =>halfWord) Test. \n"); Uart_Printf(" Base Address is: %x\n",RWBase);

Uart_Printf(" Memory Units is: %x\n",RWNum); Uart_Printf(" Access Memory Times is: %d\n",i); Uart_Printf("\n Press any key to continue... \n"); Uart_Getch();

(*(char *)(RWBase +RWNum+i*step)) = (*(char *)(RWBase +i*step));

}

Uart_Printf(" Memory Read/Write(C code =>Byte) Test. \n"); Uart_Printf(" Base Address is: %x\n",RWBase); Uart_Printf(" Memory Units is: %x\n",RWNum); Uart_Printf(" Access Memory Times is: %d\n",i); Uart_Printf("\n Press any key to continue... \n"); Uart_Getch();

Uart_Printf(" Memory Test Success! \n");

Uart_Printf("\n << CACHE >> Test. Y/y to continue,any key skip it.\n"); input_char = Uart_Getch();

if(input_char == 'Y' || input_char == 'y') Test_CACHE();

}

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Embedded Systems Development and Labs; The English Edition

4.1.7 Exercises

Write a program to read and write a consequent RAM memory space using assembly and C language.

4.2 I/O Interface Lab

4.2.1 Purpose

●Get familiar with the ARM chip and the I/O interface devices.

●Learn to interface the ARM chip with the LED chip.

4.2.2 Lab Equipment

● Hardware: Embest S3CEV40 hardware platform, Embest Standard/Power Emulator, PC. ● Software: Embest IDE 2003, Windows 98/2000/NT/XP operation system.

4.2.3 Content of the Lab

The ARM chip I/O ports are normally used with other I/O pins. Get familiar with the method of configuring the ARM I/O port via programming. Implement the lighting and winking LED1, LED2 of the hardware board.

4.2.4 Principles of the Lab

The S2C44B0X has 71 multi functional I/O pins that combine 7 groups of I/O interfaces.

●2 nine bits I/O interface (port E and F).

●2 eight bits I/O interface (port D and G).

●1 sixteen bits I/O interface (port C).

●1 ten bits I/O interface (port A).

●1 eleven bits I/O interface (port B).

Each of the port can be configured through registers by software to meet the requirements of different configurations. Before running the main program, each of the pins that will be used should be configured. If some of these I/O pins are not used, they could be configured as I/O ports.

1. S3C44B0X I/O Port Related Registers

(1)Port Control Register (PCONA-G): In S3C44B0X, most of the pins are multiplexed. Therefore, the functions for each pin must be selected. The PCONn (port control register) determines which function is used for each pin. If PG0 - PG7 are used as wakeup signal in power down mode, these ports must be configured in interrupt mode.

(2)Port Data Register (PDATA-G)

If these ports are configured as output ports, data can be written to the corresponding bits of PDATn. If Ports are configured as input ports, the data can be read from the corresponding bits of PDATn.

(3) Port Pull-Up Register (PUPC-G)

The port pull-up resistor controls the pull-up resistor enable/disable of each port group. When the corresponding

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Embedded Systems Development and Labs; The English Edition

bit is 0/1, the pull-up resistor of the pin is enabled/disabled.

(4) External Interrupt Control Register

The 8 external interrupts are activated through various signaling methods that are programmed in the EXTINT register. The signaling methods available are: low level trigger, high level trigger, falling edge trigger, rising edge trigger, and both edge triggers for the external interrupt request

Table 4-12 to Table 4-18 show the pin definitions of each port.

Table 4-12 Port A

PCONA access address: 0X01D20000

PDATA access address: 0X01D20004

PCONA reset value: 0X1FF

Table 4-13 Port B

PCONB access address: 0X01D20008

PDATB access address: 0X01D2000C

PCONB reset value: 0X7FF

Table 4-14 Port C

PCONC access address: 0X01D20010

PDATC access address: 0X01D20014

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Embedded Systems Development and Labs; The English Edition

PUPC access address: 0X01D20018

PCONC reset value: 0X0FF0FFFF

Table 4-15 Port D

PCOND access address: 0X01D2001C

PDATD access address: 0X01D20020

PUPD access address: 0X01D20024

PCOND reset value: 0XAAAA

Table 4-16 Port E

PCONE access address: 0X01D20028

PDATE access address: 0X01D2002C

PUPE access address: 0X01D20030

PCONE reset value: 0X25529

Table 4-17 Port F

PCONF access address: 0X01D20034

PDATF access address: 0X01D20038

PUPF access address: 0X01D2003C

PCONF reset value: 0X00252A

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Embedded Systems Development and Labs; The English Edition

Table 4-18 Port G

PCONG access address: 0X01D20040

PDATG access address: 0X01D20044

PUPG access address: 0X01D20048

PCONG reset value: 0XFFFF

2. The Description of the Circuit

In Table 4-13 PB9 and PB10 pins are defined as outputs and are connected to LED1 and LED2. Figure 4-5 shows the circuit connections for the LED1 and LED2. The anodes of LED1 and LED2 are connected to the pin 47 of S3C44B0X which is VDD33. VDD33 pin provides a 3.3V dc voltage. The cathodes of LED1 and LED2 are connected to pin 23 (PB9) and 24 (PB10), respectively. These two pins belong to Port B and have been configured as outputs. Writing a 1 or a 0 to the specific bit of the PDATAB register can make the pin’s output low or high. When the pin 23, 24 is low, the LEDs will be on (lit). When the pin 23, 24 is high, the LEDs will be off.

Figure 4-5. Connection diagram to LED 1 and LED 2

4.2.5 Operation Steps

1)Prepare the Lab environment. Connect the Embest Emulator to the target board. Connect the target board UART0 to the PC serial port through the serial cable provided by the Embest development system.

2)Run the PC Hyper Terminal (set to 115200 bits per second, 8 data bits, none parity, 1 stop bits, none flow control).

3)Connect the Embest Emulator to the target board. Open the LED_test.ews project file that is located in the …\EmbestIDE\Examples\Samsung\S3CEV40 directory. Compile and link the project. Connect to the target

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Embedded Systems Development and Labs; The English Edition

board and download the program.

NOTE: please note that the debug window should be set as in Figure 4-5a:

Figure 4-5a. Debug settings for the project

4)Watch the hyper terminal output. The following should be displayed: Embest 44B0X Evaluation Board (S3CEV40)

LED Test Example

5)The LED1 and LED2 will be in the following states:

LED1 on Æ LED2 on Æ LED1 and LED2 onÆ LED2 off Æ LED1 off.

4.2.6 Sample Programs

/*****************************************************************************

*File Name: light.c

*Author: embest

*Description: control board's two LEDs on or offf

*History:

*****************************************************************************/

/*--- include files ---*/ #include "44b.h" #include "44blib.h"

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Embedded Systems Development and Labs; The English Edition

/*--- function code---*/ /*************************************************************************

*modify:

*comment:

**************************************************************************/

void Led_Test()

{

/* 1 on -> 2 on -> all on -> 2 off -> 1 off */ leds_off();

Delay(1000); led1_on(); Delay(1000); led1_off(); led2_on(); Delay(1000); leds_on(); Delay(1000); led2_off(); Delay(1000); led1_off();

}

/***************************************************************************

*modify:

*comment:

***************************************************************************/

void leds_on()

{

Led_Display(0x3);

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