mc68hc11ea9 Freescale Semiconductor, Inc, mc68hc11ea9 Datasheet - Page 27

• Manufacturer Part Number: mc68hc11ea9
• Description: 8-bit Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

PIOC — Port I/O Control
STAF — Strobe A Interrupt Status Flag
STAI — Strobe A Interrupt Enable
CWOM — Port C Wire-OR Mode
HNDS — Handshake Mode
OIN — Output or Input Handshaking
PLS — Pulse/Interlocked Handshake Operation
EGA — Active Edge for Strobe A
INVB — Invert Strobe B
MC68HC11EA9
MC68HC11EA9TS/D
RESET:
This bit is set when a selected edge occurs on Strobe A. Clearing it depends on the state of the HNDS
and OIN bits. In simple strobed mode or in full handshake mode, STAF is cleared by a read of the PIOC
register followed by a read of PORTCL register. In output handshake mode, STAF is cleared by reading
the PIOC register followed by a write to PORTCL register.
When bit I in the condition code register is clear and STAI is set, STAF (when set) will request an inter-
rupt.
CWOM affects all eight port A pins.
When clear, strobe A acts as a simple input strobe to latch data into PORTCL, and strobe B acts as a
simple output strobe which pulses after a write to port B. When set, a handshake protocol involving port
C, STRA, and STRB is selected (see the definition for the OIN bit).
This bit has no meaning or effect when HNDS = 0.
This bit has no meaning if HNDS = 0. When interlocked handshake operation is selected, strobe B, once
activated, stays active until the selected edge of strobe A is detected. When pulsed handshake opera-
tion is selected, strobe B is pulsed for two E cycles.
0 = No edge detected on strobe A
1 = The selected edge (rising or falling) has been detected on strobe A
0 = STAF will not generate an interrupt when set.
1 = STAF will generate an interrupt when set.
0 = Port C outputs are normal CMOS outputs
1 = Port C outputs act as open-drain outputs
0 = Simple strobe mode
1 = Full input or output handshake mode
0 = Input handshake
1 = Output handshake
0 = Interlocked handshake selected
1 = Pulsed handshake selected
0 = Falling edge of strobe A selected. When output handshake is selected, port C lines obey the
1 = Rising edge of strobe A selected. When output handshake is selected, port C lines obey the
0 = Active level is logic zero
1 = Active level is logic one
data direction register while STRA is low, but port C is forced to output when STRA is high.
data direction register while STRA is high, but port C is forced to output when STRA is low.
STAF
BIT 7
0
STAI
6
0
Freescale Semiconductor, Inc.
For More Information On This Product,
CWOM
5
0
Go to: www.freescale.com
HNDS
4
0
OIN
3
0
PLS
2
0
EGA
1
0
BIT 0
INVB
0
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