ADLINK Technology cPCI-7200 User Manual page 36

IN_REQ
IN_ACK
PC's Main Memory
O_REQ & O_ACK for Digital Output
1. Digital Output Data is moved from PC memory to FIFO o f 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
PC's Main
Memory
26 Operation Theorem
2
Bus mastering
DMA data Transfer
5
4
5
Bus mastering
Digital Output FIFO
DMA data Transfer
1
Digital Input DATA
Latch Digital Input
or Digital Output
4
Digital Input FIFO
Digital Output DATA
Move Data to
Digital Output
2
1
3
3