mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 121

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

6.5.6.2
6.5.6.3
Freescale Semiconductor
Reset:
Reset:
PTFDDn
PTFPEn
PTFDn
Field
Field
Field
7–0
7–0
7–0
W
W
R
R
PTFDD7
PTFPE7
Port F Data Register Bits — For port F pins that are inputs, reads return the logic level on the pin. For port F
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port F pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTFD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
Data Direction for Port F Bits — These read/write bits control the direction of port F pins and what is read for
PTFD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port F bit n and PTFD reads return the contents of PTFDn.
Internal Pull Enable for Port F Bits — Each of these control bits determines if the internal pullup device is
enabled for the associated PTF pin. For port F pins that are configured as outputs, these bits have no effect and
the internal pull devices are disabled.
0 Internal pullup device disabled for port F bit n.
1 Internal pullup device enabled for port F bit n.
Port F Data Direction Register (PTFDD)
0
Port F Pull Enable Register (PTFPE)
0
7
7
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
PTFDD6
PTFPE6
Figure 6-29. Internal Pull Enable for Port F Register (PTFPE)
0
0
6
6
Figure 6-28. Port F Data Direction Register (PTFDD)
Table 6-27. PTFDD Register Field Descriptions
Table 6-28. PTFPE Register Field Descriptions
Table 6-26. PTFD Register Field Descriptions
PTFDD5
PTFPE5
0
0
5
5
PTFDD4
PTFPE4
0
0
4
4
Description
Description
Description
PTFDD3
PTFPE3
3
0
3
0
PTFDD2
PTFPE2
0
0
2
2
Parallel Input/Output Control
PTFDD1
PTFPE1
0
0
1
1
PTFDD0
PTFPE0
0
0
0
0
6-17