mc9s08gt16a Freescale Semiconductor, Inc, mc9s08gt16a Datasheet - Page 87

• Manufacturer Part Number: mc9s08gt16a
• Description: Hcs08 Microcontrollers 8-bit Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor
PTAPE[7:0]
PTAD[7:0]
Reset
Reset
Field
Field
7:0
7:0
W
W
R
R
PTAPE7
PTAD7
Port A Data Register Bits — For port A pins that are inputs, reads return the logic level on the pin. For port A
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 A pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTAD 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.
Pullup Enable for Port A Bits — For port A pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled provided the corresponding PTADDn is 0. For port A pins that are configured
as outputs, these bits are ignored and the internal pullup devices are disabled. When any of bits 7 through 4 of
port A are enabled as KBI inputs and are configured to detect rising edges/high levels, the pullup enable bits
enable pulldown rather than pullup devices.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
0
0
7
7
PTAPE6
PTAD6
0
0
6
6
Figure 6-9. Pullup Enable for Port A (PTAPE)
Figure 6-8. Port A Data Register (PTAD)
Table 6-2. PTAPE Field Descriptions
MC9S08GT16A/GT8A Data Sheet, Rev. 1
PTAPE5
Table 6-1. PTAD Field Descriptions
PTAD5
0
0
5
5
PTAPE4
PTAD4
0
0
4
4
Description
Description
PTAPE3
PTAD3
3
0
3
0
PTAPE2
PTAD2
0
0
2
2
PTAPE1
PTAD1
0
0
1
1
Parallel Input/Output
PTAPE0
PTAD0
0
0
0
0
87