PropBasic - ina[8..15]

camelot2

hi, what I want to do is read the input register, P8 thru P15,
and assign it to a variable like in spin·· value := ina[noparse][[/noparse]8..15]
·
How can I do this in PropBasic ??· thanks

Gerry Keely

I think all you need do is

Pins PIN 8..15 INPUT
value·var long

Program Start
Start:
value·=Pins
·END

Gerry

JonnyMac

Keep in mind that the order of your declaration affects the value you will get back from the pins -- be mindful of the LSB pin and MSB pin assignments. For example:

Switch          PIN     7..0

and...

Switch          PIN     0..7

... have the LSB and MSB pins reversed, so having %00001111 on P7..P0 will return $0F with the first declaration, but $F0 with the second due to the reversal. As with Spin, this can be a useful feature.

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Jon McPhalen
Hollywood, CA

camelot2

thanks Gerry and JonneyMac for the replies. I tried it but it
needs 16 ticks of the system clk. If I use value1 = ina then
only 4 ticks are needed but then I have to apply a mask to get
the desired bits. I want to use this 100 times to accumalate
ADC data which would require variables value1 thru value100. Any
thoughts as how to do this will be appreciated

JonnyMac

Use inline assembly if speed is a concern. Remember, compilers must be generalized and will not always give us the results we would hand-code.

ASM
    mov     __temp1, ina
    shr     __temp1, #8
    and     __temp1, #$FF
  ENDASM

At the end of this routine __temp1 holds the bits you seek; you can mix this into your PropBASIC code.

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Jon McPhalen
Hollywood, CA