Hardware Coding

[cxzuk]

Hi there,

Could someone point me in to the best place(s) of a list of what hardware there is avaible, what it can do and a small tutorial of how it works?

Id like to learn about all hardware stuff the GP2x can offer, such as the blitter, sound, LED, etc..

Cheers

Mike

 

[Squidge]

The MMSP2 datasheet is available on the Wiki.

 

[cxzuk]

The MMSP2 datasheet is available on the Wiki.

Which is missing =)

 

[cxzuk]

Is there any other places i can get information from? as http://wiki.gp2x.org/ is still down.

Cheers

 

[Daid]

http://daid.mine.nu/pub/MP2520F_Manual_Eng_V1.0.pdf
That should take care of the manual.

However a small tutorial isn't in there.

 

[cxzuk]

http://daid.mine.nu/pub/MP2520F_Manual_Eng_V1.0.pdf
That should take care of the manual.

However a small tutorial isn't in there.

Thanx for that.. im sure ill be bugging all for more help later!

 

[cxzuk]

Ok, im very new to this =) Could someone help me?

Ive got the manual above /\... and im trying to understand it abit...

Lets take the contrast as an example... (p434).

16.2.6.2 Contrast
The contrast of Luminance is controlled by ISP_CNTRSTGAIN.
Contrast Control Register (ISP_CNTRSTGAIN)
Address : C000 3036h
Bit R/W Symbol Description Reset Value
[15:3] W Reserved Must be 0 0
[2:0] R/W ISP_CNTRSTGAIN
Contrast Gain Control
0 : 0.25, 1 : 0.5, 2 : 0.75, 3 : 1.0, 4 : 1.25, 5 : 1.5, 6 : 1.75, 7 : 2.0
3’h3
TABLE 16-21. CONTRAST CONTROL REGISTER (ISP_CNTRSTAIN)

I presume that the 0-2 bits are the contrast settings. with a value of 0-7 (so 3bits)..

Now how exactly do i access that?

Mike

 

[TheMinder]

For any other links you may want to try eg. http://wiki.gp32spain.com/index.php/Art%C3%ADculos_varios

 

[Daid]

Ok, im very new to this =) Could someone help me?

Ive got the manual above /\... and im trying to understand it abit...

Lets take the contrast as an example... (p434).

16.2.6.2 Contrast
The contrast of Luminance is controlled by ISP_CNTRSTGAIN.
Contrast Control Register (ISP_CNTRSTGAIN)
Address : C000 3036h
Bit R/W Symbol Description Reset Value
[15:3] W Reserved Must be 0 0
[2:0] R/W ISP_CNTRSTGAIN
Contrast Gain Control
0 : 0.25, 1 : 0.5, 2 : 0.75, 3 : 1.0, 4 : 1.25, 5 : 1.5, 6 : 1.75, 7 : 2.0
3’h3
TABLE 16-21. CONTRAST CONTROL REGISTER (ISP_CNTRSTAIN)

I presume that the 0-2 bits are the contrast settings. with a value of 0-7 (so 3bits)..

Now how exactly do i access that?

Mike

Here is an example for you:

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#ifdef WIN32
#else
#include <sys/mman.h>
#include <linux/fb.h>
#include <unistd.h>
#include <stropts.h>

int memfd;

volatile unsigned long *memregs32;
volatile unsigned short *memregs16;

unsigned char initphys (void)
{
	memfd = open("/dev/mem", O_RDWR);
	if (memfd == -1)
	{
		printf ("Open failed for /dev/mem\n");
		return 0;
	}

	memregs32 = (unsigned long*) mmap(0, 0x10000, PROT_READ|PROT_WRITE, MAP_SHARED, memfd, 0xc0000000);
	
	if (memregs32 == (unsigned long *)0xFFFFFFFF) return 0;
	memregs16 = (unsigned short *)memregs32;

	return 1;
}

void closephys (void)
{
	close (memfd);
}
#endif

void LowPowerMode()
{
#ifdef WIN32
  return;
#else
  SetClock(25);
  
	if (!initphys()) return;
	
  //Turn off backlight
  memregs16[0x106E>>1] &=~0x0004;
  //Turn off LCD controller
  memregs16[0x2800>>1] &=~0x0001;
  //Set LCD to sleep mode
  memregs16[0x1062>>1] |= 0x0004;
  
	closephys();
#endif
}

void EndLowPowerMode(unsigned int NewSpeed)
{
#ifdef WIN32
  return;
#else
  SetClock(NewSpeed);
	if (!initphys()) return;
	
  //Set LCD from sleep mode
  memregs16[0x1062>>1] &=~0x0004;
  //Turn on LCD controller
  memregs16[0x2800>>1] |= 0x0001;
  //Turn on backlight
  memregs16[0x106E>>1] |= 0x0004;
  
	closephys();
#endif
}

This code accesses registers:
C000 106E (memregs16[0x106E>>1]) for turning on/off the backlight (that register controlls a GIO pin, where the backlight is connected to)
C000 2800 (memregs16[0x2800>>1]) for turning off the internal LCD controller (look it up in the manual)
and
C000 1063 (memregs16[0x1063>>1]) for setting the actual LCD screen in 'sleep' mode.

(that I mmap in every routine is a bit of a design bug, better to call the initphys() on program start and closephys() on program end)
(also note that I'm not 100% sure that my low power mode currently works at all, turning every thing off seemed to work, but dunno if everything comes up right again, that's WIP)

You could access the register you want with:
memregs16[0x3036] = (MyPersonalGainVariable & 0x7);
(after doing initphys() ofcourse)

 

[scanti]

You might also want to check out Rlyeh's Minimal Library. You might find you are trying to reinvent the wheel.

Edit: The link above is a bit out of date. A newer version of the minimal library is in the SquidgeSNES SVN.