IC-MB4_15 Datasheet, PDF (26/40 Pages) IC-Haus GmbH – BiSS INTERFACE MASTER

iC-MB4
BiSS INTERFACE MASTER
CONTROL COMMUNICATION
preliminary
Rev B2, Page 26/40
For the interim storage of register information read out
from or writing to the slaves, iC-MB4 has an individual
storage area (addresses 0x80 . . . 0xBF) which can tem-
porarily store up to 64 bytes of data. Just one single
command starts the transmission (writing to the slave
or read from the slave). The slave addressed is set by
the SLAVEID(2:0) and the first address for the register
data access is set by REGADR. The transfer of register
data may take longer than a sensor data transfer cycle,
so that the content of the sensor data RAM is then often
obsolete.
Configuration of Register Communication
REGBYTES
Addr. 0xE3; bit 5:0
R/W
0x00
After transfer: no register communication error
0x01 . . .
0x3F
After transfer: number of successfully transferred
registers before register communication error
Table 21: Register transmitted successfully
CHSEL(1)
0
1
CHSEL(2)
0
1
Addr. 0xE4; bit 0
R/W
Channel 1 not used ^∗
Channel 1 used for control communication
Addr. 0xE4; bit 1
R/W
Channel 2 not used
Channel 2 used for control communication ^†
RDATA
Addr. 0x80 . . . 0xBF;
R/W
bit 7:0
0x00 . . .
0xFF
RDATA: register data
(64 bytes, bidirectional)
Table 17: Register data
REGADR
Addr. 0xE2; bit 6:0
R/W
0x00 . . .
0x7F
Register address
Table 18: Register access start address
WNR
Addr. 0xE2; bit 7
R/W
0
Read register data
1
Write register data
Table 19: Register access direction
Table 22: Channel mapping for control communication
SLAVEID
0 ...
7
Addr. 0xE5; bit 5:3
R/W
Slave ID that addresses the register access
Table 23: Slave ID of accessed slave
iC-MB4 does support autonomous register communi-
cation with BiSS C and BiSS B, REGVERS is set to
present protocol type. On register write access with
extended SSI the BiSS C protocol type needs to be
selected.
REGVERS
Addr. 0xE5; bit 6
R/W
0
Register communication BiSS A/B
1
Register communication BiSS C
Registers start address REGADR, number of bytes
REGNUM and slave ID SLAVEID stipulate from which
slave register address onwards how many bytes are
to be written to or read out from which specific slave.
A byte count of 0 entered for REGNUM signals the
transmission of a single register value; a 63 indicates
the transmission of 64 register values. In the register
REGBYTES a 0 is indicated and readable if register
communication has proved error free. In the event of
an register communication error the number of correctly
read or written registers is indicated in REGBYTES.
Table 24: Type of protocol for register access
CTS
Addr. 0xE5; bit 7
R/W
0
Command/instruction communication
1
Register communication
Table 25: Type of control communication
The CTS parameter was called MSEL in former
MB100 or iC-MB3 data sheets.
REGNUM
Addr. 0xE3; bit 5:0
R/W
0x00
Register count = 1
0x01 . . .
0x3F
Register count = REGNUM(5:0)+1
Table 20: Register quantity of access(-1)
∗ _{Channel 1 is selected if CHSEL(2:1)=0.}
† _{Channel 2 is not available with iC-MB4 TSSOP24.}
HOLDCDM
Addr. 0xE5; bit 0
R/W
0
Clock line high at end of cycle
1
Clock line constant with CDM bit until start of next
cycle
Table 26: Length of CDM bit