
preliminary
preliminary
iC-PVS
LINEAR/OFF-AXIS
BATTERY-BUFFERED ABSOLUTE POSITION HALL SENSOR
Rev A2, Page 37/51
lute position data format as defined in chapter Absolute
Data Format on page 26. All values are transmitted
MSB first. Table 9 gives a brief overview.
NTOA_BISS : Fixed or Adaptive BiSS Timeout
The
BiSS
slave can provide a fixed or an adaptive
BiSS
timeout depending on the setting of parameter
NTOA_BISS. For fastest communication speed, it is
recommended to use the adaptive timeout.
If NTOA_BISS = 1, a fixed nominal timeout of 20
µ
s is
used (refer to Elec. Char. item no. 302 and A01).
If NTOA_BISS = 0, the slave automatically adapts the
BiSS
timeout length to ensure fastest communication.
The
BiSS
Slave measures 1.5 periods of MA (from the
first falling to the second rising edge) of each
BiSS
frame and calculates an adaptive timeout as follows:
T
SAMPLE
=
4
3
∗
ffast
Where ffast is the system clock frequency (refer to Elec.
Timeout
Min.
Max.
t
tout
1.5
∗
T
BISS
1.5
∗
T
BISS
+ 3.0
∗
T
SAMPLE
Table 50: Adaptive timeout calculations
For more information on the
BiSS
adaptive time-
out, refer to
BiSS
application note AN23 at
NTOA_BISS
Addr. 0x07; bit 7
reset: 0
Code
Value
0
Adaptive
BiSS
timeout
1
Fixed
BiSS
timeout
Table 51: Fixed or Adaptive BiSS Timeout
Control Communication
The Control Communication uses the CDM and CDS
bits of several consecutive
BiSS
frames for reading and
writing of the slave registers and the transmission of
commands to selected or all slaves.
Cycle
nCDM
CDM
Latch
IPO(5:0)
CRC(5:0)
Clock MAI
Data SLO
t
cycle
timeout
Single Cycle Data
Err,Warn
t
out
LSB
nE
LSB
CDS
Ack Start
MSB
MSB
MSB
nW
LSB
RC(39:0)
Figure 17:
BiSS
protocol showing Control Communication
BiSS protocol commands
The following BiSS interface protocol commands are
implemented.
CD Channel: BiSS Protocol Commands
CMD
Availability
Function
Addressed
00
Yes
Activate Single-Cycle Data channels
01
Yes
Deactivate control communication
10
—
Reserved
11
—
Reserved
Broadcast (all slaves)
00
Yes
Deactivate Single-Cycle data channels
01
Yes
Activate control communication
10
—
Reserved
11
—
Reserved
Table 52: BiSS Protocol Commands