User manual

RC200/203 Manual
www.celoxica.com Page 18
7. Tristate nRDWR.
8. Set nCS high.
4.4.7 Writing data to the CPLD from the FPGA
To writ
nd data bus if not already tristated.
0ns.
nable the data bus.
.
9. Tristate the data bus.
4.4.8 Transferring data between the FPGA and host
o the RC200 FPGA by accessing CPLD address
To writ (via the parallel port) to the FPGA:
.
To read nd write it to the host via the parallel port:
h.
5. Set nRDWR low.
e from the RC200 FPGA to the CPLD:
1. Set up the address a
2. Wait at least 1
3. Set nCS low.
4. Wait at least 10ns.
5. Set nRDWR high and e
6. Wait at least 40ns.
7. Tristate nRDWR
8. Set nCS high.
The parallel port can read and write data t
0. The process is controlled by the CPLD.
e data from the host
1. Set nRDWR low
2. Set PnCS low.
3. Send the data.
4. Set PnCS high.
5. Set nRDWR high.
data from the FPGA a
1. Set nRDWR hig
2. Set PnCS low.
3. Read the data.
4. Set PnCS high.