epc120
CS
SCK
SI
D1
D0
Dn
A0
A1
A2
A3
A4
A8
A9
C1
C2
R0
R1
R2
R3
R4
C0
Register Address
or Cmd Extension
Device Address
Command
Data
Figure 18: Communication to the sensor devices (Broadcast Command)
Command List
Name
Command
Code
C0 .. C2
Command
Extension Code
R0 .. R4
Function
Mode
Number of data bits
on 2-wire bus
D0..Dn
Returned
Data
SCAN
NOP
000
000
010
011
101
110
111
111
Scan
Broadcast
Direct
both
62
0
Yes
Yes
Yes
No
No operation
Read
READ
WRITE
ADRA
PROG
TEST
Register address
Register address
97
62
62
62
80
62
Write to volatile register
Address allocation
Program
both
Broadcast
both
No
Register address
10000
No
Test mode
both
Yes
No
RESET
11001
Reset the device
Table 7: Command list
both
Remarks:
•
•
Additional SCK clock cycles have no effect.
The telegram length on the 2-wire bus is given in the number of data clock cycles. It allows to calculate the minimum interval between
two commands.
•
•
If an SPI command is given while another command is being transmitted on the 2-wire bus, the new command is ignored.
The READ and WRITE commands in the direct access mode require 2 additional SCK cycles.
Command SCAN
The command SCAN enables the addressed device, times the ongoing operation or fetches the scan result. The operation of the command
SCAN is described more in detail in Chapter Error: Reference source not found.
CS
SCK
SI
D0
N
D1
D2
D3
D4
D20
E0
E3
D5
Figure 19: Timing of the results of a SCAN command
The bit N indicates whether a new result has been received. D 0...D4 contains the address, D11...D20 contains the returned data, E0...E3 contains
an error code. D5...D10 are empty.
© 2011 ESPROS Photonics Corporation
Characteristics subject to change without notice
19
Datasheet epc12x - V2.1
www.espros.ch
EPC [ ESPROS PHOTONICS CORP ]
