S9S08AW16A FREESCALE [Freescale Semiconductor, Inc], S9S08AW16A Datasheet - Page 97

• Manufacturer Part Number: S9S08AW16A
• Description: HCS08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

1
1
6.7.7
Port D parallel I/O function is controlled by the registers listed below.
Freescale Semiconductor
PTDDD[3:0]
Bits 7 through 4 are reserved bits that must always be written to 0.
Bits 7 through 4 are reserved bits that must always be written to 0.
PTDD[3:0]
Reset
Reset
Field
Field
3:0
3:0
W
W
R
R
Port D I/O Registers (PTDD and PTDDD)
Port D Data Register Bits — For port D pins that are inputs, reads return the logic level on the pin. For port D
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 D pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTDD 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 D Bits — These read/write bits control the direction of port D pins and what is read for
PTDD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port D bit n and PTDD reads return the contents of PTDDn.
R
R
0
0
7
7
R
R
0
0
6
6
Figure 6-26. Data Direction for Port D (PTDDD)
Table 6-17. PTDDD Register Field Descriptions
Table 6-16. PTDD Register Field Descriptions
Figure 6-25. Port D Data Register (PTDD)
MC9S08AC16 Series Data Sheet, Rev. 8
R
R
0
0
5
5
R
R
0
0
4
4
Description
Description
PTDDD3
PTDD3
3
0
3
0
PTDDD2
PTDD2
1
0
0
2
2
1
Chapter 6 Parallel Input/Output
PTDDD1
PTDD1
0
0
1
1
PTDDD0
PTDD0
0
0
0
0
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