Replace Shiftout with spi

[Ron Marcus]

euh.. SHIFTOUT is already SPI!

Give us more details!

I believe Pedro means hardware SPI. With that assumption, it would be good to know which processor you are working with Pedro. Shiftout/in works very well and it's easy(Thanks Melabs!) buuuuut... It can be slow. How fast do you need to go?

Ron

[Pedro Santos]

Hi Ron

Yes, i mean the hardware SPI
Like You say the Shifout work very good but it is slow, i need to send a byte
quickly to a lcd and perhaps with the hardware SPI pin can i have more speed
The controller that i use is PIC 18F452

Have You a sample code to do that, don't forget it must sent the MSBFIRST

Thanks

Regards

Pedro

[Darrel Taylor]

Pedro,

There's a sample SPI program on the meLabs website.

http://www.melabs.com/resources/samples.htm

Look for spimast.bas

HTH,

[Pedro Santos]

Hi

Yes i see the sample on melabs site but don't understand how to sent
with the spi out pin the msbit first, say bit7, bit6, bit5, ... bit0

Thanks for help
Pedro

[Darrel Taylor]

The MSSP always sends data MSB first.
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[Pedro Santos]

Hello Darrel

my board work correct with this instruction
Shiftout sdata , sclk ,MSBFIRST, [var_out]

Do You know the correct SPI setup to use the hardware SPI to do that?

I try with this and have no function
'spi setup
SSPEN VAR SSPCON1.5 'SSP Enable bit
CKP VAR SSPCON1.4 'Clock Polarity Select
SMP VAR SSPSTAT.7 'Data input sample phase
CKE VAR SSPSTAT.6 'Clock Edge Select bit

TRISC = 0

CKP = 0 'clock idle low 'have changed to 1 for testing but no ok
CKE = 0 'transmit on idle to active transition 'have changed to 1 for testing
'but no ok
SSPIF = 0 'clear SPI interrupt
SMP = 0

main:
SSPEN = 1 'enable SPI pins
SSPBUF = var_out 'send array variable
Return

Have a idea how to fix that?

Thank You

Regards

Pedro

[Darrel Taylor]

For MSBFIRST, you have it correct.

CKP = 0
CKE = 0

Which PIC are you using?
What OSC frequency are you using?
What is it sending data to?

Are you connected to the SDO/SCK pins of the pic?
SDO(PIC) to SDI(slave), AND SCK(PIC) to SCK(slave).

Also, in this code...

main:
    SSPEN = 1 'enable SPI pins 
    SSPBUF = var_out 'send array variable
Return

Since no subroutine was called, the program will reset when it gets to the Return.
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