epc110
Detailed Command & Result Descriptions
Command NOP: No operation
The command NOP can be used to fetch data without sending a new command – see next section Readout of Returned Results.
Readout of Returned Results
The results/data at output pin SO depend on the previous transmitted command to input pin SI.
Two ways to readout this data are possible:
1. Either it can be fetched in parallel of transmitting a next command
2.
or by sending NOP commands just by toggling SCK while CS is low.
Remarks:
•
•
•
The data is represented with the LSB first.
Data is valid on positive edge of clock SCK while CS is low.
If more clock toggles SCK are issued than data can be fetched, zeros are transmitted.
Command READ: Read register Rn
With the command READ the registers of the RAM and ROM memory can be read register by register.
The command extension “Register address” defines the requested register for reading it out.
After command transmission the expected result data can be readout on the SO pin.
Result readout frame (telegram):
CS
SCK
SO
N
R0
R1
R2
R3
R4
D0
Dn
Figure 16: Timing Result Data
Result data format:
Data Bits
Function
N
Not used, have to be ignored
5 bit register address
R0...R4
D0...D15
16 bit returned data of the corresponding register (one complete register)
Table 5: Result of a READ command
Command WRITE: Write to RAM register 16 - 18
Data can be written into the volatile RAM register 16 – 18 by using the command WRITE. The command extension “Register address” selects
the register. It is followed by the data to be written.
In VMOD = 1 it is possible to write to registers only, if the corresponding register in the ROM has not been written yet. It is not possible to write
directly to a ROM register. If the data has to be stored into the ROM register, a subsequent command PROG has to be used.
In VMOD = 0 the RAM registers can be written at anytime.
Command PROG
The command PROG transfers the data from the RAM register to the corresponding ROM register. See chapter Parameter Programming for a
detailed description.
Command RESET
The command RESET resets the device and initiates a startup.
© 2011 ESPROS Photonics Corporation
Characteristics subject to change without notice
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Datasheet epc110 - V2.1
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EPC [ ESPROS PHOTONICS CORP ]
