IC-MD_17 Datasheet, PDF (15/30 Pages) IC-Haus GmbH – 48-BIT QUADRATURE COUNTER

iC-MD 48-BIT QUADRATURE COUNTE^pR^reliminary
WITH RS422 RECEIVER AND SPI/BISS INTERFACE
Rev B1, Page 15/30
Figure 5: Zero-Codification: reference position acquisition
UPD REGISTER
The register UPD is load at every index pulse with the ^NUPDVAL
Addr. 0x0A;
R
value of the "reference counter", it is the number of 0
UPD value valid
AB edges between the last two index pulses (value of 1
UPD value not valid
the reference counter). It is used to check that any AB
pulse was lost.
Table 28: Update Register Not Valid
The status bit UPDVAL (table 49) signals that a new
UPD value is available (UPD register was loaded and
still not read).
The following diagram shows the value of REF and
UPD after activating the zero codification function when
counting in negative direction.
UPD(23:0)
Addr. 0x0A;
R
UPD register value
0xXXXXXX
Table 27: Update Register Value
5000
5005
5000
5005
5000
5005
2510
2490
2515
2485
2520
2480
2525
Z
Z
Z
Z
Z
Z
Z
Z
Bit ZCEN=1
Negative counting direction
REF
UPD
CNT
0
-2510
-2510
-2510
-2510
-2510
-2510
X
-2510
-2490
-2515
-2485
-2520
-2480
X
0+n
-2490+n
-2515+n
-5000+n
-5520+n
-10000+n
Figure 6: REF and UPD registers in negative direction