write_bitfieldhex.m

这是一个关于MATLAB的函数

function dummy = write_bitfieldhex(nn,index,data)
% Private. Bitfield hexadecimal write.
%   Copyright 2002 The MathWorks, Inc.
%   $Revision: 1.2 $ $Date: 2002/05/14 19:46:57 $

error(nargchk(2,3,nargin));
if ~ishandle(nn),
    error('First Parameter must be a BITFIELD Handle.');
end
if nargin==2,   
    data = index;   
end;
% Is data a valid input
if ~ischar(data) & ~(iscellstr(data) & length(data)==1)
    error('DATA must be must be an array of hexidecimal strings ');
end

% Convert from hex to numeric
data = hex2dec(data) * (2^nn.offset);  % shift data by the its offset

% Reshape value according to ARRAYORDER property
if strcmp(nn.arrayorder,'row-major'),
    data = reshape(permute(data,[2 1]),1,[]);
else  
    data = reshape(data,1,[]);
end

% Data is numeric format

% Do we have sufficent values ?
nvalues = numel(data);
nvaldef = prod(nn.size);
if nvalues < nvaldef,
    % warning('DATA has less elements than specified numeric array, DATA will only be applied to beginning of memory area');
elseif nvalues > nvaldef,
    % warning('DATA has more elements than specified numeric array, DATA will be be limited to defined memory area');
    data = data(1:nvaldef);  % Truncate!
end
 
% Convert numeric values into array of AUs 
%  where each column is the the AUs necessary for one numeric value
%  The data will be little-endian (swapped later if necessary)
%  thus cc.write([1 256]), where storageunitspervalue = 3, represent = 'unsigned', bitsperstorageunit = 8
%  fdata = 
%    1  0
%    0  1
%    0  0
data = { dec2hex( data ) };
zerostr = '0';
uidata = [];
for i=1:length(data),
    mustlen = round( nn.bitsperstorageunit * nn.storageunitspervalue/4 ); % total bits in a value div (4 bits in a character)
    needzerochars = mustlen-length(data{i});
    if needzerochars > -1
        data{i}  = [zerostr(ones(1,needzerochars)) data{i}];
    else
        warning(['Overflow: Saturation was required to fit into the specified numeric range']);
        data{i}  = data{i}(1+abs(needzerochars):end);
    end
    newdata  = hex2dec( flipud(reshape(data{i},mustlen/nn.storageunitspervalue,[])') )';
    uidata = horzcat(uidata, newdata);
end
uidata = uidata';

% Endianness swap (if necessary), Little endian only
if strcmp( nn.endianness,'big') & (nn.storageunitspervalue > 1),
    uidata = flipud(uidata);
end    

% Call base class (memoryobj) to get unformatted data
memdata  = read_memoryobj(nn);
memdata  = reshape(double(memdata),nn.storageunitspervalue,[]);
% temp   = dec2bin(memdata);
base     = dec2bin( bitshift((2^nn.length-1), ...
					nn.prepad+nn.offset,nn.prepad+nn.offset+nn.length), nn.wordsize);
baseinv = dec2bin( (2^nn.wordsize-1) - bin2dec(base) );
% base  = bin2dec(flipud(reshape(   base,[],nn.storageunitspervalue)'));
baseinv = bin2dec(flipud(reshape(baseinv,[],nn.storageunitspervalue)'));

if strcmp( nn.endianness,'big') & (nn.storageunitspervalue > 1),
    base    = flipud(base);
    baseinv = flipud(baseinv);
end
memdata = bitand(memdata,baseinv); % zero out bit field only
uidata  = bitor(memdata,uidata);    

% Write raw values to memory
if nargin == 2,
    write_memoryobj(nn,uidata);
else % timeout % index version - one value only!
    write_memoryobj(nn,(index-1).*nn.storageunitspervalue+1,uidata);
end

% [EOF] write_bitfieldhex.m