Omron CJ - INSTRUCTIONS REFERENCE MANUAL 07-2009 Reference Manual page 427

3. Instructions
256-to-8 bit Conversion
When the fourth (leftmost) digit of C is 1, DMPX(077) finds the locations of the leftmost (highest bit
address) or rightmost (lowest bit address) ON bits in one or two 16-word ranges of source words. The
locations of these bits are written to R beginning with the specified byte.
l =0 (Convert one 16-word range.)
Finds leftmost bit
(Highest bit address)
256-to-8 bit decoding
(The location of the leftmost bit in the
16-word range (m) is written to R.)
R
Hint
As shown at right, 16 to 4 encoding consists of
converting the bit number (m) of the leftmost or
rightmost bit that has 1 set among the 16 bits to a
4-bit binary value.
As shown at right, 256 to 8 encoding consists of
converting the bit number (m) of the leftmost or
rightmost bit that has 1 set among the 256 bits to
an 8-bit binary value.
Precaution
16-to-4 bit conversion
When two or more digits are being converted, DMPX(077) will write the values to the digits in R from
right to left and will wrap around to the rightmost digit after the leftmost digit, if necessary.
256-to-8 bit conversion
When two bytes are being converted, DMPX(077) will write the values to the bytes in R from right to left
and will wrap around to the rightmost byte if the leftmost byte (byte 1) has been specified as the starting
byte.
390
C
Leftmost Rightmost
bit bit
n=1 (Start with byte 1.)
15
0
Rightmost ON bit
255
0
Rightmost ON bit
m 0
0 1 0 0
Leftmost ON bit
m
4 bits
m
0 1 0
8 bits
CS/CJ/NSJ Series Instructions Reference Manual (W474)
0
0
Leftmost ON bit
m