Peter Bigot <bigotp <at> acm.org> writes:
>
> On Thu, Aug 4, 2011 at 10:22 AM, Alexandru Stefan
> <alexandru.stefan <at> cloudbit.ro> wrote:
> > Hello,
> >
> > I am currently working on two inline routines to read and write
> > data to
> > addresses >64k.
> >
> > This is the 'write' routine:
> >
> >
> > static inline __attribute__((always_inline)) void
> > flash_write(uint32_t addr,
> > uint16_t val){
> >
> > __asm__ __volatile__ (
> > "dint \n"
> > "nop \n"
> > "pushx.a r15 \n"
> > "movx.a %[addr], r15 \n"
> > "movx %[val], @r15 \n"
> > "popx.a r15 \n"
> > "eint \n"
> > :
> > :[addr] "r"(addr), [val] "r"(val)
> > );
> > }
> >
> > and this is the asm code it generates:
> >
> > static inline __attribute__((always_inline)) void
> > flash_write(uint32_t addr,
> > uint16_t val){
> >
> > __asm__ __volatile__ (
> > 315c: 2e 44 mov @r4, r14
> > 315e: 1f 44 02 00 mov 2(r4),
> > r15 ;0x0002(r4)
> > 3162: 1d 44 04 00 mov 4(r4),
> > r13 ;0x0004(r4)
> > 3166: 32 c2 dint
> > 3168: 03 43 nop
> > 316a: 00 18 .word 0x1800; ????
> > 316c: 4f 12 push.b r15
> > 316e: 00 18 .word 0x1800; ????
> > 3170: 4f 4e mov.b r14, r15
> > 3172: 40 18 .word 0x1840; ????
> > 3174: 8f 4d 00 00 mov r13,
> > 0(r15) ;0x0000(r15)
> > 3178: 00 18 .word 0x1800; ????
> > 317a: 7f 41 pop.b r15
> > 317c: 32 d2 eint
>
> 0: 32 c2 dint
> 2: 03 43 nop
> 4: 00 18 4f 12 pushx.a r15
> 8: 00 18 4f 4e movx.a r14, r15
> c: 40 18 8f 4d movx r13, 0(r15) ;0x00000(r15)
> 10: 00 00
> 12: 00 18 7f 41 popx.a r15
> 16: 32 d2 eint
> 18: 30 41 ret
>
> Your disassembler isn't up to date.
>
> Peter
> >
> > uint32_t address = 0x11110UL;
> > uint16_t val = 0x33;
> >
> > flash_write(address, val);
> > }
> >
> > The main question is why is used the simple MOV instruction
> > instead of the
> > extended version?
> >
> > Regards,
> > Alex
> >
> >
> > ----------------------------------------------------------------------------
--
> > BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA
> > The must-attend event for mobile developers. Connect with experts.
> > Get tools for creating Super Apps. See the latest technologies.
> > Sessions, hands-on labs, demos & much more. Register early & save!
> > http://p.sf.net/sfu/rim-blackberry-1
> > _______________________________________________
> > Mspgcc-users mailing list
> > Mspgcc-users <at> lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/mspgcc-users
> >
>
> ------------------------------------------------------------------------------
> BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA
> The must-attend event for mobile developers. Connect with experts.
> Get tools for creating Super Apps. See the latest technologies.
> Sessions, hands-on labs, demos & much more. Register early & save!
> http://p.sf.net/sfu/rim-blackberry-1
>
Thanks for the reply.
I have implemented some simple read/write routines (both for byte and
word operations) from >64k addresses and found some unusual problems:
1) When using only byte operations with the variables located in RAM
(local to functions), everything worked ok.
2) When writing first a value located in the flash (global static array)
and then values from RAM, the read/write routines didn't work as
expected.
3) When alternating byte/word operations, some of them didn't work (the
read value was incorrect)
I am just beginning working with assembly and, although I have a clear
idea of what I need to do, it's quite possible that I've made some
errors in the routines:
static inline __attribute__((always_inline)) void
flash_write_byte(uint32_t addr, uint8_t val)
{
__asm__ __volatile__ (
"dint \n"
"nop \n"
"mova %[addr], r15 \n"
"movx %[val], @r15 \n"
"eint \n"
:
:[addr] "r"(addr), [val] "m"(val)
);
}
static inline __attribute__((always_inline)) uint8_t
flash_read_byte(uint32_t addr)
{
uint8_t result;
__asm__ __volatile__ (
"dint \n"
"nop \n"
"mova %[addr], r15 \n"
"movx @r15, %[result] \n"
"eint \n"
:[result] "=m"(result)
:[addr] "r"(addr)
);
return result;
}
static inline __attribute__((always_inline)) void
flash_write_word(uint32_t addr, uint16_t val)
{
__asm__ __volatile__ (
"dint \n"
"nop \n"
"mova %[addr], r15 \n"
"movx %[val], @r15 \n"
"eint \n"
:
:[addr] "r"(addr), [val] "r"(val)
);
}
static inline __attribute__((always_inline)) uint16_t
flash_read_word(uint32_t addr)
{
uint16_t result;
__asm__ __volatile__ (
"dint \n"
"nop \n"
"mova %[addr], r15 \n"
"movx @r15, %[result] \n"
"eint \n"
:[result] "=m"(result)
:[addr] "r"(addr)
);
return result;
}
Thanks,
Alex
------------------------------------------------------------------------------
BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA
The must-attend event for mobile developers. Connect with experts.
Get tools for creating Super Apps. See the latest technologies.
Sessions, hands-on labs, demos & much more. Register early & save!
http://p.sf.net/sfu/rim-blackberry-1
_______________________________________________
Mspgcc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/mspgcc-users
