MC68HC08AZ0 Datasheet, PDF (349/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
I/O Ports
Port G
Port G
Port G is a 3-bit general-purpose bidirectional I/O port.
Port G data
register (PTG)
The port G data register contains a data latch for each of the three port
G pins.
PTG $000A
Read:
Write:
Reset:
Alternate Function
Bit 7
6
5
4
3
2
0
0
0
0
0
PTG2
Unaffected by reset
KBD2
= Unimplemented
Figure 19. Port G data register (PTG)
1
PTG1
KBD1
Bit 0
PTG0
KBD0
PTG[2:0] — Port G Data Bits
These read/write bits are software-programmable. Data direction of
each bit is under the control of the corresponding bit in data direction
register G. Reset has no effect on port G data.
KBD[2:0] — Keyboard Inputs
The keyboard interrupt enable bits, KBIE[2:0], in the keyboard
interrupt control register (KBICR), enable the port G pins as external
interrupt pins. See Keyboard Module (KB) on page 319.
Data direction
register G (DDRG)
Data direction register G determines whether each port G pin is an input
or an output. Writing a logic one to a DDRG bit enables the output buffer
for the corresponding port G pin; a logic zero disables the output buffer.
DDRG
$000E
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
0
0
0
0
DDRG2 DDRG1 DDRG0
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 20. Data direction register G (DDRG)
21-io
MOTOROLA
I/O Ports
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MC68HC08AZ0
347