502
Conversion Instructions Section 3-12
Description DMPX(077) can perform 16-to-4 bit or 256-to-8 bit conversions. Set the left-
most digit of C to 0 to specify 16-to-4 bit conversion and set it to 1 to specify
256-to-8 bit conversion.
16-to-4 bit Conversion
When the fourth (leftmost) digit of C is 0, DMPX(077) finds the locations of the
leftmost or rightmost ON bits in up to 4 source words and writes these loca-
tions to R beginning with the specified digit. (Set the third digit of C to 0 to find
the leftmost ON bits or 1 to find the rightmost ON bits.)
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.
The following diagram shows some example values for C and the 16-to-4 bit
conversions that they produce.
R
m
C
Leftmost bit
n=2 (Start with digit 2.)