Memory Allocation
Section 4-2
63
Unit in Comparison Mode
In Comparison Mode Indirect Addressing can be used to define the Comparison
Values per Counter that you want to use. The number of CV’s (M) defines the size
of the CV Data block (size = M x 10 words). If you want to use multiple CV’s you
are recommended to use consecutive CV’s starting from CV 0 (i.e. CV 0, 1, 2, 3
→
M - 1) in order to save memory occupation.
Note
If you do not want the Comparison Values to be consecutive and only intend to use
two CV’s (e.g. CV 0 and CV 7) then you still have to define the number of CV’s (M)
to be 8. In order to prevent configuration errors from happening you should make
sure that the data of CV’s 1 to 6 is also valid, although you do not intend to use CV
1 to 6.
Configuring Indirect
Addressing
Indirect Addressing with the Unit in Range or Comparison Mode is specified in the
Special I/O Unit DM Area for every Counter. You must specify the memory area
(EM/DM) and the address (00000 to 32760) of the first word where the Range/CV
data is to be stored. Like this you are able to specify any address that is available
in EM or DM. By specifying the number of Ranges or Comparison Values per
Counter you determine the number of words with Range/CV data that are allo-
cated for every Counter. For every Range 6 words and for every Comparison
Value 10 words are allocated.
Counter 'c'
c = 1 or 2
# of CV's M
(0
M
≤
8)
≤
EM (=0) / DM (=1)
Area
Indirect Address k(c)
(00000 to 32760)
Data CV 0
Data CV M *-1
Data CV 1
Data CV 2
Data CV 3
k(c)
EM/DM:
Special I/O Unit DMA Area:
Size of CV Data block:
Number of CV's (=M) x 10 words
* Assumed that M
≠
0. By default M=0 which means that no CV's will be used
