Thanks to all for the replies! I learned a lot!
I decided to use the SPI module, it works fine!
Best Regards
Bruno
On 11/10/05, David Brown [EMAIL PROTECTED] wrote:
I suspect you misunderstand what optomization means, especially when
applied to a small microcontroller. Choosing -Os (or -O2,
I suspect you misunderstand what optomization means, especially when
applied to a small microcontroller. Choosing -Os (or -O2, which is very
similar) tells the compiler to generate small and fast code. It is not
dangerous or risky. Gcc does have a few risky optomisation passes that you
can
On Wed, 9 Nov 2005 21:25, Mike S. wrote:
Thanks for the reply Daniel O'Connor, but I usually don't use the
optimization until I try a couple of and optimization techniques. I
already had some bad experiences with the optimization in some Texas
Instruments DSPs...
If you don't tell GCC to do
From: David Kelly [EMAIL PROTECTED]
[...]
People keep saying C isn't fast enough. I don't belive it. First
attempt:
#include avr/io.h
#define CLOCK_B (10)
#define BIT_B (11)
void
myjunk(uint8_t byte) {
uint8_t i;
for( i = 0 ; i 8 ; i++ ) {
PORTA |= CLOCK_B;
void write_data (Word towrite, Byte nbits)
{
Byte n;
for(n = 0; n nbits; n++)
{
CLK_HIGH;
if( towrite (0x0001 n))
{
SDIO_HIGH;
}
else
{
SDIO_LOW;
}
CLK_LOW;
}
}
This will give very slow code, because a left shift by a
You'll find this modification / correction helps with speed because you don't
have to evaluate (1n) each time through the loop. Only a single bit shift on
the 16-bit value is required.
#define ADS1210_PORT PORTF
#define SDIO_BIT 0x04 /* 0b 0100 PORTF.2*/
#define CLK_BIT 0x02 /*
Hi,
I think there are two problems with the code:
- using 16 bit data
- shifting by a variable number of bits
An optimization would be to write a funktion which only shifts up to 8
bit, and to shift the data every time by one bit.
Regards,
Nils
original code:
void write_data (Word towrite,
On Wed, Nov 09, 2005 at 09:00:58AM -0500, Dave Hansen wrote:
From: David Kelly [EMAIL PROTECTED]
[...]
People keep saying C isn't fast enough. I don't belive it. First
attempt:
[...]
It might be tough to do better on AVR. My standard SPI routine uses a
do-while loop, which might save an
Hello to all,Can anyone tell me the best (faster) way to implement bit shifting (serial synch protocol-in a bit bang fashion-) with two general purpose digital pins (one pin for data the other for clock)? Using C is not fast enough! I need assembly!
Thanks in advance Best Regards
(I use the
Hi Mike,
Do you have any code for the C implementation of what you are trying to
do? What protocol are you implementing? is it SPI one way? TWI? what
frequency will the clock be? Will you be using interrupts in any way, or
how will you do your communication? 90CAN128 is a high performance uC
On Wed, 9 Nov 2005 02:15, Mike S. wrote:
Hello to all,
Can anyone tell me the best (faster) way to implement bit shifting
(serial synch protocol
-in a bit bang fashion-) with two general purpose digital pins (one
pin for data the other
for clock)? Using C is not fast enough! I need
On Tue, Nov 08, 2005 at 03:45:54PM +, Mike S. wrote:
Hello to all,
Can anyone tell me the best (faster) way to implement bit shifting
(serial synch protocol -in a bit bang fashion-) with two general
purpose digital pins (one pin for data the other for clock)? Using C
is not fast enough! I
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