Writing a Parallel Communication Driver
D–5
Publication 17706.5.20 - June 1997
To receive data from the host, the KFC15/KFCD15:
1. Sets pin 11(Busy) to 1.
2. Reads data.
3. Sets pin 10 (Acknowledge) to 0 then 1.
4. Sets pin 11 (Busy) to 0.
At this point if the host has more data to send, it can repeat the above
procedure until the entire packet is sent. Then, if data is expected
from the KFC15/KFCD15, the host should set pin 17 (Select Input)
to 0 to enter either Byte or Nibble mode.
Data Transfer in Byte Mode
To send data in Byte mode from the KFC15/KFCD15 to the host, the
KFC15/KFCD15:
1. Checks that the host’s pin 14 (Auto Feed) is set to 0.
2. Places data on the data lines.
3. Sets pin 10 (Acknowledge) to 0 then 1.
To receive data in Byte mode, the host:
1. Sets pin 14 (Auto Feed) to 1.
2. Reads the data.
3. Sets pin 1 (Strobe) to 0 then 1.
If there is more data to send, the KFC15/KFCD15:
"
Sets pin 15 (Error) and pin 12 (P. End) to 0.
and the host should:
"
Set pin 14 (Auto Feed) to 0, then repeat its receive procedure.