Learn about peripherals one by one for_ARM interrupt keyboard

Outer board schematic

Four-layer board schematic diagram (core board)

This board uses a total of 10 keys, namely EINT1~EINT7

So the corresponding registers are GPH1_1~GPH0_7..

First, check the chip manual to see the descriptor of the GPH0 register.

GPH0,1,2,3: 32 in/out pin –CAM IF channel, Key pad, External Wakeup (up-to 32-bit)

The main idea is that GPHO can be woken up externally.

GPH0CON[7]  [31:28]  0000 = Input, 0001 = Output, 0010 = WU_INT[7]  0000

GPH0CON[6]  [27:24]  0000 = Input, 0001 = Output, 0010 = WU_INT[6]  0000

GPH0CON[5]  [23:20]  0000 = Input, 0001 = Output, 0010 = WU_INT[5]  0000

GPH0CON[4]  [19:16]  0000 = Input, 0001 = Output, 0010 = WU_INT[4]  0000

GPH0CON[3]  [15:12]  0000 = Input, 0001 = Output, 0010 = WU_INT[3]  0000

GPH0CON[2]  [11:8]  0000 = Input, 0001 = Output, 0010 = WU_INT[2]  0000

GPH0CON[1]  [7:4]  0000 = Input, 0001 = Output, 0010 = WU_INT[1]  0000

PAD CONTROL    S5PC100 USER’S MANUAL (REV1.0)

2.2-36

GPH0CON[0]  [3:0]  0000 = Input, 0001 = Output, 0010 = WU_INT[0]  0000

Then let's look at the wake-up interrupt configuration register:

5.6.1 Wakeup Interrupt 0_7 Configuration (WU_INT0_7_CON, R/W, Address = 0xE030_0E00)

The value of WU_INTx_y_CON[n] means that 000 = Low level, 001 = High level, 010 = Falling edge triggered,

011 = Rising edge triggered, 100 = Both edge triggered

It means wake-up interrupt configuration register

000 is low level valid 001 is high level valid 010 is falling edge trigger 011 is rising edge trigger valid 100 is both edges are acceptable

Let's take a look at the wake-up interrupt mask register:

Wakeup Interrupt 0_7 Mask (WU_INT0_7_MASK, R/W, Address = 0xE030_0F00)

The value of FLTENx_y[n] means that 0= disable, 1=enable. The value of FLTSELx_y[n]means that 0 = delay

filter, 1 = digital filter

FLTENx_y[n] 0 means enable or disable 1 means enable or disable

FLTSELx_y[n] 0 is delay filter 1 is digital filter

Reserved [31:8]  Reserved 

WU_INT0_7_MASK [n]  [n]

Mask for WU_INT[n]

0 = Enabled,1 = Masked (n=0~7)

After reading these registers, you can implement key interrupts:

First understand the interrupt process: (here is GPH0)

①: Enable the interrupt mode of the pin --- that is, GPH0CON = GPH0CON & (~(0xf)) | 0x2<<4 <------- >GPH0CON[1] Here, key1 is used temporarily. According to the schematic diagram, key1 is enter1, which is GPH0CON[1]

②: Set the interrupt trigger mode (that is, configure the wake-up interrupt register)

WKUP_INT0_7_CON[1]

WKUP_INT0_7_CON = ( WKUP_INT0_7_CON & (~(0x7<<4)))  | (0X2<<4);

Set falling edge trigger

010

0111<<4

~11100000 = 0001 1111 | 0010 <<4

0001 1111 | 0010 0000

= 0011 1111

So digits 4-6 should be 011, so that's right, the eight digits above are 0 - 7

③: Enable interrupt mask register (mask)

WKUP_INT0_7_MASK = WKUP_INT0_7_MASK &(~(0x1<<1)) ;

0010 ~ =0, so 0 enables or disables interrupts.

④: Enable VIC interrupt on GPH0

VIC0INTERRUPT.VIC0INTENABLE |=1<<1; //It is the second one from the bottom up, so it is 1

Why VIC0 is used here? It is provided to us by the chip manual.

⑤: Register the interrupt function and implement the do_irq function and interrupt service function and clear the interrupt bit at the end

VIC0VECTADDR.VIC0VECTADDR1 = (unsigned int )key1_int;

void key1_int()

{

    printf("key1_int\n");

    VIC0ADDRESS =0;

    VIC1ADDRESS =0;

    VIC2ADDRESS =0;

    WKUP_INT0_7_PEND = 1<<1;

/*This is the description of waiting for interrupt WAKEU_PENDING

*/ Wakeup Interrupt 0_7 Pending (WU_INT0_7_PEND, R/W, Address = 0xE030_0F40)

Field  Bit  Description  Reset Value

Reserved [31:8]  Reserved  0

WU_INT0_7_PEND [n]  [n]

This bit is set if WU_INT [n] is pending.

Writing ‘1’ makes this bit clear. (n=0~7)

0

Note. Even though WU_INT0_7_MASK [n] is masked, this can be pended.

}

void do_irq() /*Implementation of do_irp function()*/

{

    printf("VIC0ADDRESS = %x\n",VIC0ADDRESS );

    ( (  void(*)(void)  )VIC0ADDRESS)();

}

About ( ( void(*)(void) )VIC0ADDRESS)();

This is actually a forced conversion of a function pointer.

It can be completely understood as void (*)();

Understand it this way.

Through the above, a key interrupt can be realized.

 /*---------------------*/

printf("keven");