Chapter 6 Parallel Input/Output Control

 

 

Table 6-36. PTFDS Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

Output Drive Strength Selection for Port F Bits. Each of these control bits selects between low and high output

PTFDSn

drive for the associated PTF pin. For port F pins configured as inputs, these bits have no effect.

 

0

Low output drive strength selected for port F bit n.

 

1

High output drive strength selected for port F bit n.

 

 

 

6.7.7Port G Registers

Port G is controlled by the registers listed below.

6.7.7.1Port G Data Register (PTGD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTGD7

PTGD6

PTGD5

PTGD4

PTGD3

PTGD2

PTGD1

PTGD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

Figure 6-40. Port G Data Register (PTGD)

 

Table 6-37. PTGD Register Field Descriptions

 

 

Field

Description

 

 

7–0

Port G Data Register Bits. For port G pins configured as inputs, reads return the logic level on the pin. For port

PTGDn

G pins configured as outputs, reads return the last value written to this register.

 

Writes are latched into all bits of this register. For port G pins configured as outputs, the logic level is driven out

 

the corresponding MCU pin.

 

Reset forces PTGD 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 pull-ups disabled.

 

 

6.7.7.2Port G Data Direction Register (PTGDD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTGDD7

PTGDD6

PTGDD5

PTGDD4

PTGDD3

PTGDD2

PTGDD1

PTGDD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

Figure 6-41. Port G Data Direction Register (PTGDD)

 

Table 6-38. PTGDD Register Field Descriptions

 

 

Field

Description

 

 

7–0

Data Direction for Port G Bits. These read/write bits control the direction of port G pins and what is read for PTGD

PTGDDn

reads.

 

0 Input (output driver disabled) and reads return the pin value.

 

1 Output driver enabled for port G bit n and PTGD reads return the contents of PTGDn.

 

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

 

 

134

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Freescale Semiconductor MCF51QE128RM Port G Registers, Port G Data Register Ptgd, Port G Data Direction Register Ptgdd