Specifications

28 •• Operation Theorem
O_REQ & O_ACK for Digital Output
1. Digital Output Data is moved from PC memory to FIFO of PCI-
7200 by using DMA data mastering data transfer.
2. Move output data from FIFO to digital output circuit.
3. Output data is ready.
4. An O_REQ signal is generated and sent to outside device.
5. After an O_ACK is got, the step 2 to step 5 will be repeated
again.
** If the FIFO is not full, the output data is moved form PC‘s main
memory to FIFO automatically.
O_REQ
O_ACK
Move Data to
Digital Output FIFO
Bus mastering
DMA data Transfer
PC's Main
Memory
2
4
3
1
Digital Output DATA
5
Digital Output