NBITS

NBITS

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Action

Set all except the specified bits to 1.

 

 

Syntax

Var = NBITS( b1 [,bn])

 

 

Remarks

Var

The BYTE/PORT variable that is assigned with the constant.

B1 , bn

A list of bit numbers that NOT must be set to 1.

 

While it is simple to assign a value to a byte, and there is special Boolean notation &B for assigning bits, the Bits() and NBits() function makes it simple to assign a few bits.

 

B = &B01111101 : how many zero’s are there?

This would make it more readable: B = NBits(1, 7)

You can read from the code that bit 1 and bit 7 are NOT set to 1.

It does not save code space as the effect is the same.

 

The NBITS() function will set all bits to 1 except for the specified bits.

It can only be used on bytes and port registers.

Valid bits are in range from 0 to 7.

 

 

See Also

BITS

 

 

Example

'--------------------------------------------------------------------------------

'name                     : bits-nbits.bas

'copyright                : (c) 1995-2005, MCS Electronics

'purpose                  : demo for Bits() AND Nbits()

'micro                    : Mega48

'suited for demo          : yes

'commercial addon needed  : no

'use in simulator         : possible

'--------------------------------------------------------------------------------

 

$regfile = "m48def.dat"                                   ' specify the used micro

$crystal = 4000000                                         ' used crystal frequency

$baud = 19200                                               ' use baud rate

$hwstack = 32                                               ' default use 32 for the hardware stack

$swstack = 10                                               ' default use 10 for the SW stack

$framesize = 40                                             ' default use 40 for the frame space

 

Dim B As Byte

 

'while you can use &B notation for setting bits, like B = &B1000_0111

'there is also an alternative by specifying the bits to set

B = Bits(0 , 1 , 2 , 7)                                   'set only bit 0,1,2 and 7

Print B

 

'and while bits() will set all bits specified to 1, there is also Nbits()

'the N is for NOT. Nbits(1,2) means, set all bits except 1 and 2

B = Nbits(7)                                               'do not set bit 7

Print B

End