Chapter 6 Parallel Input/Output Control

 

 

Table 6-41. PTGDS Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

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

PTGDSn

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

 

0

Low output drive strength selected for port G bit n.

 

1

High output drive strength selected for port G bit n.

 

 

 

6.7.8Port H Registers

Port H is controlled by the registers listed below.

6.7.8.1Port H Data Register (PTHD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTHD7

PTHD6

PTHD5

PTHD4

PTHD3

PTHD2

PTHD1

PTHD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

Figure 6-45. Port H Data Register (PTHD)

 

Table 6-42. PTHD Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTHDn

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

 

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

 

the corresponding MCU pin.

 

Reset forces PTHD 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.

 

 

6.7.8.2Port H Data Direction Register (PTHDD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTHDD7

PTHDD6

PTHDD5

PTHDD4

PTHDD3

PTHDD2

PTHDD1

PTHDD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

Figure 6-46. Port H Data Direction Register (PTHDD)

 

Table 6-43. PTHDD Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTHDDn

reads.

 

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

 

1 Output driver enabled for port H bit n and PTHD reads return the contents of PTHDn.

 

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

 

 

136

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Freescale Semiconductor MCF51QE128RM Port H Registers, Port H Data Register Pthd, Port H Data Direction Register Pthdd