Contec DIO-32DM2-PE, User Manual

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4. Function
40
DIO-32DM2-PE
Interrupt (at the time of bus master transfer)
The product provides the following two interrupt functions during bus mastering:
- Causes an interrupt each time the specified number of items are transferred.
- Causes an interrupt upon completion of transfer.
These interrupts can be posted to applications by using the function of API-PAC(W32).
If transfer is completed with an error when no bus can be seized or when it is missed, for example, this
product stops the transfer and generates a transfer completion interrupt. You can tell whether a
transfer error has occurred by checking the status.
Status, count
The following types of bus mastering status (error) are provided.
Status Contents
DIODM_STATUS_BMSTOP
Indicates that bus master transfer has been completed.
DIODM_STATUS_PIOSTART
Indicates that PIO input/output has been started.
DIODM_STATUS_PIOSTOP
Indicates that PIO input/output has been stopped.
DIODM_STATUS_TRGIN
Indicates that a start signal has been input in external start mode.
DIODM_STATUS_OVERRUN
Indicates that a start signal has been input twice or more in external start mode.
Transfer can continue with no problem.
Error Contents
DIODM_STATUS_FIFOEMPTY
Indicates that the FIFO buffer is empty. This is mainly because of a heavy load
on the system that makes it late for bus master transfer. Take action such as
decreasing the transfer rate or system load.
DIODM_STATUS_FIFOFULL
Indicates that the FIFO buffer is full. This is mainly because of a heavy load on
the system that makes it late for bus master transfer. Take action such as
decreasing the transfer rate or system load.
DIODM_STATUS_SGOVERIN
Indicates a buffer overflow. The number of data items to be transferred exceeds
the buffer size. Increase the buffer size.
DIODM_STATUS_TRGERR
Indicates that the start and stop signals have been input at the same time in
external start mode. Check how the external start and stop signals are input.
DIODM_STATUS_CLKERR
Indicates that the next clock signal is input during data input in external clock.
If the status is set, sampling cannot be done by using the specified external clock.
Consider decreasing the period of external clock.
DIODM_STATUS_SLAVEHALT
Indicates that a stop trigger from the slave has caused forced termination.
Check for any error on the slave side.
DIODM_STATUS_MASTERHALT
Indicates that a stop trigger from the master has caused forced termination.
Check for any error on the master side.
These types of status can be obtained by using the function of API-PAC(W32).
The 32bit or 64bit transfer count can be obtained by using the function of API-PAC(W32). The
transfer count is obtained as the number of data items already transferred to user application memory in
input mode or as the number of data items already output to an external device in output mode.