
MOTOROLA
MC68341 USER’S MANUAL
4- 37
DDRA
$013
76543210
DD7
DD6
DD5
DD4
DD3
DD2
DD1
DD0
RESET:
00000000
Supervisor/User
4.3.5.4 PORT A DATA REGISTER (PORTA). PORTA affects only pins configured as
discrete I/O. A write to PORTA is stored in the internal data latch, and if any port A pin is
configured as an output, the value stored for that bit is driven on the pin. A read of PORTA
returns the value at the pin only if the pin is configured as discrete input. Otherwise, the
value read is the value stored in the internal data latch. This register can be read or written
at any time.
PORTA
$011
76543210
P7
P6
P5
P4
P3
P2
P1
P0
RESET:
UUUUUUUU
Supervisor/User
4.3.5.5 PORT B PIN ASSIGNMENT REGISTER (PPARB). PPARB controls the function
of each port B pin. Any set bit defines the corresponding pin to be an IRQ≈ input as
defined in Table 4-6. Any cleared bit defines the corresponding pin to be a discrete I/O pin
controlled by the port B data and data direction registers. The MODCK signal has no
function after reset. PPARB is configured to all ones at reset to provide for MODCK,
IRQ7– IRQ1 . This register can be read or written at any time.
PPARB
$01F
76543210
PPARB7
(IRQ7)
PPARB6
(IRQ6)
PPARB5
(IRQ5)
PPARB4
(IRQ4)
PPARB3
(IRQ3)
PPARB2
(IRQ2)
PPARB1
(IRQ1)
PPARB0
(MODCK)
RESET:
11111111
Supervisor Only
4.3.5.6 PORT B DATA DIRECTION REGISTER (DDRB). DDRB controls the direction of
the pin drivers when the pins are configured as I/O. Any set bit configures the
corresponding pin as an output; any cleared bit configures the corresponding pin as an
input. This register affects only pins configured as discrete I/O. This register can be read
or written at any time.
DDRB
$01D
76543210
DD7
DD6
DD5
DD4
DD3
DD2
DD1
DD0
RESET:
00000000
Supervisor/User
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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