i am optimizing my code with inline assembler

Why?

i need fast refresh, and with c code, the led panel flickers
arduino is not that fast

The compiler optimizes your code too. What makes you think you can do a better job, Rumpelstiltskin?

i know, but if you dont try.. right?

btw i end up having a code 10 times faster

seeing the code in asm,  also helps you understand things that could be optimized

i am optimizing my code with inline assembler

Why?

to have you ask why

anybody ?

Hello,

[sorry , i could not post this in "Syntax..." on the forum, donno why...]

i am optimizing my code with inline assembler but i got questions...

ex: i have to acess elements of a 2 dimentional array one by one and refer them as operands that gonna be mapped to registers

Code:

__asm__ __volatile__
(

    "mov r24,%[LEDS]" "\n\t"

 : [LEDS] "+r" (leds[0][0].value) ::
);

how do i adress a whole array instead of having to assign 1 register per operand ?

the problem is that if i use too many operands, the compiler generates a lot of code to load data in registers (before my code)
and a lot of code to load modified registers back to the memory (after my code)

so i thought i could do the adressing myself by storing the adress of an array for instance in the z register
and the parsing memory, read/write the required values, but how to do that ?

also the compiler generates a lot of push before my actual asm code (without any pops ??? wtf?)
does anybody knows why and how to supress this, i lose a lot of cycles for nothing as the whole code runs in the "void loop(){...}" section

ex:

Code:

void loop()
{

     400: 4f 92        push r4
     402: 5f 92        push r5
     404: 6f 92        push r6
     406: 7f 92        push r7
     408: 8f 92        push r8
     40a: 9f 92        push r9
     40c: af 92        push r10
     40e: bf 92        push r11
     410: cf 92        push r12
     412: df 92        push r13
     414: ef 92        push r14
     416: ff 92        push r15
     418: 0f 93        push r16
     41a: 1f 93        push r17
     41c: df 93        push r29
     41e: cf 93        push r28
     420: 0f 92        push r0
     422: cd b7        in r28, 0x3d ; 61
     424: de b7        in r29, 0x3e ; 62
     426: c0 90 04 04 lds r12, 0x0404
     42a: 8c 2c        mov r8, r12
     42c: 99 24        eor r9, r9
     42e: 70 91 05 04 lds r23, 0x0405
     432: 87 2f        mov r24, r23
     434: 90 e0        ldi r25, 0x00 ; 0
     436: f0 90 36 01 lds r15, 0x0136
     43a: 2c 01        movw r4, r24
     43c: 44 0c        add r4, r4
     43e: 55 1c        adc r5, r5
     440: 44 0c        add r4, r4
     442: 55 1c        adc r5, r5
     444: 48 0e        add r4, r24
     446: 59 1e        adc r5, r25
     448: 88 e7        ldi r24, 0x78 ; 120
     44a: 90 e0        ldi r25, 0x00 ; 0
     44c: 9c 01        movw r18, r24
     44e: 82 9e        mul r8, r18
     450: c0 01        movw r24, r0
     452: 83 9e        mul r8, r19
     454: 90 0d        add r25, r0
     456: 92 9e        mul r9, r18
     458: 90 0d        add r25, r0
     45a: 11 24        eor r1, r1
     45c: 48 0e        add r4, r24
     45e: 59 1e        adc r5, r25
     460: f2 01        movw r30, r4
     462: ec 5c        subi r30, 0xCC ; 204
     464: fe 4f        sbci r31, 0xFE ; 254
     466: 43 81        ldd r20, Z+3 ; 0x03
     468: 54 81        ldd r21, Z+4 ; 0x04
     46a: 91 81        ldd r25, Z+1 ; 0x01
     46c: 30 91 06 04 lds r19, 0x0406
     470: 3a 01        movw r6, r20
     472: b9 2e        mov r11, r25
     474: a3 2e        mov r10, r19
     476: 27 2f        mov r18, r23
     478: 26 95        lsr r18
     47a: 26 95        lsr r18
     47c: 26 95        lsr r18

}

plz help

thx

Hello, i bought that same module
can you put your code on the forum?
i dont understand how to adress the chip from the links given on this page
do you have any datasheet ?
thx

nobody ?

is there any ADK specialist who can tell me if it is gonna work ?

i found this android 4 motherboard http://dx.com/p/diy-android-4-0-motherboard-development-board-green-180172

so the simpler question would be
as it is android 4.0 and usb host 2.0
is the ADK arduino board compatible with this ?

thx

Hello,

i use my sony xperia with the ADK and it works quiet fine

but as i plan to use an android dev board instead of my own mobile phone, i got trouble finding informations about possible compatibility

i plan to purchase one of these but i have to be sure the usb communication with the ADK is going to work

APC Board : http://apc.io/specifications/

XODROID : http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G133999328931

if anyone could guide me on those
or any other suggestion is welcome

thx