Lpc2000

I don't believe the ARM has bit access instructions.  So when the 
compiler reads the ioset register (or a byte of it?) according to 
the datasheet you will read what was previously written.  So you 
risk setting unwanted pins (likely).
James

--- In lpc2000@yahoogroups.com, Leonardo Santos <lsantos@p...> wrote:
> Hello All:
> 	I'm working with a LPC2106 using the GCC 3.4.4 toolchain 
(GCC + binutils 2.15 
> + newlib 1.13).	I wrote a union and a structure to access 
the P0 pins 
> individually, like this:
> 
> typedef struct {
> 	int p0	: 1;
> 	int p1	: 1;
> 	int p2	: 1;
> (...)
> 	int p30	: 1;
> 	int p31	: 1;
> }port_t;
> 
> typedef union {
> 	port_t pins;
> 	unsigned int reg;
> } ioreg;
> 
> typedef struct {
> 	ioreg iopin;
> 	ioreg ioset;
> 	ioreg iodir;
> 	ioreg ioclr;
> }gpio_t;
> 
> So I declare a pinter like
> 
> 	volatile gpio_t *gpio = 0xE0028000;
> 
> If I access the registers using 
> 
> 	if( gpio->iopin.reg & 0x01 )
> 
> or 
> 
> 	gpio->ioset.reg |= 0x00008000;
> 
> Everithing works fine! But if I try a code like this:
> 
> 	gpio->ioset.pins.p15 = 1;
> 
> To set P0.15, P0.23 and P0.31 are set too! I had tried this code 
in my Linux 
> workstaion and it works just fine. The compiles setting I'm using 
are 
> 
> arm-elf-gcc -c -Wall -D GCC_ARM7 -mcpu=arm7tdmi -Tlpc2106-rom.ld -
Wcast-align 
> -O3
> 
> So I'm compiling it in ARM mode. Any clues? Is this a compiler 
issue ( I'm not 
> using the right parameters)?
> 
> Thanks a lot!
> 
> -- 
> This is Linux country.
> On a quiet night, you can hear Windows reboot.
> 
> Leonardo Pereira Santos
> Engenheiro de Projetos
> PD3 Tecnologia
> av. Pará 330/202
> (51) 3337 1237
> 
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