MC68711E20CFNE3 Datasheet, PDF (103/242 Pages) –

Parallel I/O Control Register
CWOM — Port C Wired-OR Mode Bit (affects all eight port C pins)
It is customary to have an external pullup resistor on lines that are driven by open-drain devices.
0 = Port C outputs are normal CMOS outputs.
1 = Port C outputs are open-drain outputs.
HNDS — Handshake Mode Bit
0 = Simple strobe mode
1 = Full input or output handshake mode
OIN — Output or Input Handshake Select Bit
HNDS must be set to 1 for this bit to have meaning.
0 = Input handshake
1 = Output handshake
PLS — Pulsed/Interlocked Handshake Operation Bit
HNDS must be set to 1 for this bit to have meaning. When interlocked handshake is selected, strobe
B is active until the selected edge of strobe A is detected.
0 = Interlocked handshake
1 = Pulsed handshake (Strobe B pulses high for two E-clock cycles.)
EGA — Active Edge for Strobe A Bit
0 = STRA falling edge selected, high level activates port C outputs (output handshake)
1 = STRA rising edge selected, low level activates port C outputs (output handshake)
INVB — Invert Strobe B Bit
0 = Active level is logic 0.
1 = Active level is logic 1.
M68HC11E Family Data Sheet, Rev. 5.1
Freescale Semiconductor
103