Notes On Developing With Cc-Link Version 2; Hardware - Renesas R-IN32 Series User Manual

R-IN32 Series CC-Link Remote device station
13.

Notes on Developing with CC-Link Version 2

13.1

Hardware

Basically, hardware structures for Versions 2 and 1 are the same. Nonetheless, please note on the following points.
(1) Version 2 Work Area
When in the Extended Cyclic setting (nx), data is transmitted/received by dividing it into n packets. Therefore, it is
necessary to store the data for n packets in a memory buffer and read/write all the data together. To avoid losing part or
all of the data, design the buffer in a way that all data packets for n transmissions/receptions can be read or written in one
operation.
(2) Switching
Though this is unnecessary for Version 2-dedicated remote device stations, if both Version 2 and Version 1 protocols
are to be supported, a switch may be required in order to toggle between Version 2 and Version 1.
(3) Polling Processing
To avoid missing a Transmission SQ from the master station, polling processing must be performed at an interval less
than 1ms. To achieve this, the CCS_REFSTB interrupt signal can be used, or an interrupt can be initiated by a timer, etc.
For details, see Section 12.3, Transmission/Reception Processing.
(4) Transmission Processing
In Version 1, writing to CCS transmission buffer could be done at any time, but in Version 2, the timing of writing to
the transmission buffer is critical. All of the polling processing described above needs processing to validate the data
written after turning ON the CCS transmission data write complete (offset address 0080h: M3SDOK) after triggered by
the falling of the CCS_REFSTB signal. Therefore, design the hardware so that it can positively detect the falling of the
CCS_REFSTB signal. For example, use an MPU that can handle interrupt triggers or embed the falling of the
CCS_REFSTB signal into an interrupt using external logic.
For details, see Section 13.3, Write Timing at Transmission.
R18UZ0056EJ0102
Dec. 28, 2018
13. Notes on Developing with CC-Link Version 2
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