IC-LNB_13 Datasheet, PDF (29/35 Pages) IC-Haus GmbH – 18-BIT OPTO ENCODER WITH SPI AND SER/PAR INTERFACES

iC-LNB 18-BIT OPTO ENCODER ^preliminary
WITH SPI AND SER/PAR INTERFACES
NOUTLO
Code
0
1
Addr. 0x11; bit 6
Internal FlexCount outputs
low
Normal operation
Table 35: Setting FlexCount outputs to low
INVZ
Code
0
1
Rev A1, Page 29/35
Addr. 0x0B; bit 4
Incremental output INCZ
not inverted
inverted
Table 39: Output inversion INCZ
Hysteresis
A hysteresis can be programmed for FlexCount. The
size of the hysteresis can be set as a multiple of the
interpolator LSB step size using parameter HYS. This
means that the resolution of the interpolator influences
the selectable hysteresis.
HYS
Code
0x0
0x1
0x2
0x3
0x4
...
0xFC
Addr. 0x0B, bit 0; Addr. 0x0A, bit 6:0
RESIPO = 0x0 RESIPO = 0x1 RESIPO = 0x2
8-bit interp. 7-bit interp. 6-bit interp.
No hysteresis No hysteresis No hysteresis
±1 LSB
No hysteresis No hysteresis
±2 LSB
±1 LSB
No hysteresis
±3 LSB
±1 LSB
No hysteresis
±4 LSB
±2 LSB
±1 LSB
±252 LSB
±126 LSB
±63 LSB
Table 36: FlexCount hysteresis
Incremental outputs
When FlexCount is enabled, incremental outputs
A/B/Z can be inverted as required using register bits
INVA, INVB, and INVZ. If the A/B/Z outputs are not
generated by FlexCount (INC = 0x07), inversion will
not function.
INVA
Code
0
1
Addr. 0x0B; bit 6
Incremental output INCA
not inverted
inverted
Table 37: Output inversion INCA
Position offset
iC-LNB’s FlexCount permits a programmable position
offset. This offset can be set as a binary value of
the maximum internal resolution (which is dependent
on interpolator resolution RESIPO) using parameter
ZPOS (not in the selected FlexCount resolution). All
values from 0 to 262,143 can be selected at 8 bits; at
7 bits the LSB must remained fixed at 0, and at 6 bits
the last two LSBs must be 0. If no position offset is set
(ZPOS = 0x0), the zero position is symmetrical with the
falling edge of the MSB (in interface operation: signal
at pin GA, Figure 19).
GA (MSB)
INCZ
INCA
INCB
ZPOS = 0x0
Figure 19: Zero position for ZPOS = 0x0
ZPOS
Code
0x0
0x1
0x2
...
0x7FFF
...
0x10000
...
0x3FFFF
Addr. 0x0C; 0x0D; 0x0E bit 3:0
Positions offset (binary)
0
1 (only with 8 bit interpolation)
2 (only with 7/8 bit interpolation)
ZPOS
32767 (only with 8 bit interpolation)
ZPOS
65536
ZPOS
262143 (only with 8 bit interpolation)
Table 40: Position offset
The length of the Z pulse can be selected using pa-
rameter Z90. It can be set to a width of 90^◦ or 180^◦
.
INVB
Code
0
1
Adr 0x0B, bit 5
Incremental output INCB
not inverted
inverted
Z90
Code
0
1
Addr. 0x0E; bit 4
Index width
180^◦
90^◦
Index gating
A
A&B
Table 38: Output inversion INCB
Table 41: Z pulse width