Polling for keystrokes

The morning is still seven points not to wake up, do not know whether it is more than a year has been accustomed to, think of freshman sophomore are nine points after waking up, and now really do not know where the spirit. As a "slot", always than a little effort, effort is not shameful, today's main task is bare metal, s5pv210 of the frequency reduction,

#define GPJ2CON * ((volatile unsigned int *) 0xe0200280)
#define GPJ2PUD * ((volatile unsigned int *) 0xe0200288)
#define GPJ2DAT * ((volatile unsigned int *) 0xe0200284)

#define APLL_CON0 * ((volatile unsigned int *) 0xe0100100)

extern void delay (void);

void Chang_clock (void)
{
Apll_con0 = Apll_con0 |0x807d0302; Only one line, embedded is like this, a short line of code, the back is not know how much information of the pages
}

void Main (void)
{

Gpj2con = 0x1111;
Gpj2pud = 0XAA;
Gpj2dat = 0xf;

Chang_clock ();

while (1)
{
Gpj2dat = 0x0;
Delay ();
Gpj2dat = 0xf;
Delay ();
}
}

Also made a bare-metal drive for button polling, as follows

#define GPJ2CON * ((volatile unsigned int *) 0xe0200280)
#define GPJ2PUD * ((volatile unsigned int *) 0xe0200288)
#define GPJ2DAT * ((volatile unsigned int *) 0xe0200284)

#define GPH2CON * ((volatile unsigned int *) 0XE0200C40)
#define GPH2PUD * ((volatile unsigned int *) 0xe0200c48)
#define GPH2DAT * ((volatile unsigned int *) 0XE0200C44)

/*
#define GPH3CON * ((volatile unsigned int *) 0XE0200C60)
#define GPH3PUD * ((volatile unsigned int *) 0xe0200c68)
#define GPH3DAT * ((volatile unsigned int *) 0XE0200C64)

Gph3con = 0x00;
Gph3pud = 0XAA;
Gph3dat = 0xFF; You cannot assign an initial value when you enter it.

*/
extern void delay (void);

void Main (void)
{
Gpj2con = 0x1111;
Gpj2pud = 0XAA;
Gpj2dat = 0xf;

Gph2con = 0x00;
Gph2pud = 0xaa;//Here is only configured with four bits, so the following is used to judge 0e,od,ob,o7
Gph2dat = 0xFF; You cannot assign an initial value when you enter it.

while (1)
{
Delay ();

if (Gph2dat = = 0x0e)
{
Gpj2dat = Gpj2dat ^1; The little girl in the class thought, genius, studied.
}

if (Gph2dat = = 0x0d)
{
Gpj2dat = Gpj2dat ^2; Every time you come in, you can take the opposite position.
}

if (Gph2dat = = 0x0b)
{
Gpj2dat = Gpj2dat ^4;
}

if (Gph2dat = = 0x07)
{
Gpj2dat =gpj2dat ^8;
}
}
}

Intelligence is not enough effort to make up, people ugly will learn more.

Polling for keystrokes