Hitachi NJI-350B User Manual
Page 142
Chapter 5 Instruction Specifications
5-92
Item number
Application instructions-20
Name
Decode
Ladder format
Condition code
Processing time (
µs)
Remark
R7F4
R7F3
R7F2
R7F1
R7F0
Average Maximum
DECO (d, s, n)
DER
ERR
SD
V
C
↕
z
z
z
z
Instruction format
Number of steps
Condition
Steps
As per the table
below.
DECO (d, s, n)
4
Bit
Word
Double word
Usable I/O
X
Y
R,
M
TD, SS,
CU, CT
WX WY
WR,
WM TC DX DY
DR,
DM
C
o
nstant
Other
d
Decode destination head I/O
{
s
Word I/O to be decoded
{
{
{
{
{
n
Number of bits to be
decoded
{ 1 to 8 (decimal)
Function
• Decodes the lower n bits of s to 2
n
and outputs '1' to the decoded bits in the bit rows between d and d + 2
n
– 1 (where n = 1
to 8). Note that the value “0” is output for bits other than the decoded bits in the bit row d + 2
n
– 1.
• If n is “0,” the instruction will not be executed, and the contents of d to d + 2
n
– 1 remain unchanged.
b15
b7
b0
d+2
n
-1
d+B
1
d
2
n
s
0BH
0
0
0
n bits (n = 1 to 8)
Notes
• Use this instruction so that d + 2
n
– 1 does not exceed the I/O range (R7BF and M3FFF). If it exceeds the I/O range, DER is
equal to '1' and the decoding is performed at the maximum range starting from d.
• Use 1 to 8 for n.
Program example
R100
LD
R100
AND DIF1
[
DECO (R000, WX0000, 4)
]
DECO (R000, WX0000, 4)
DIF1
Program description
• When WX0000 = H000F, R00F, which is the 15th bit from R000 among the bits indicated by the lower four bit values of
WX0000, is set to “1” upon leading of R100.
DE
CO (d, s,
n)
Processing time (
µs)
n
Average
Maximum
1
105
–
2
115
–
3
195
–
4
195
–
5
317
–
6
481
–
7
829
–
8
1586
–