Freescale Semiconductor MCF51QE128RM manual Port J Registers, Port J Data Register Ptjd

Models: MCF51QE128RM

1 424
Download 424 pages 63.71 Kb
Page 138
Image 138

Chapter 6 Parallel Input/Output Control

 

 

Table 6-46. PTHDS Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

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

PTHDSn

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

 

0

Low output drive strength selected for port H bit n.

 

1

High output drive strength selected for port H bit n.

 

 

 

6.7.9Port J Registers

Port J is controlled by the registers listed below.

6.7.9.1Port J Data Register (PTJD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTJD7

PTJD6

PTJD5

PTJD4

PTJD3

PTJD2

PTJD1

PTJD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

Figure 6-50. Port J Data Register (PTJD)

 

Table 6-47. PTJD Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTJDn

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

 

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

 

the corresponding MCU pin.

 

Reset forces PTJD 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.

 

 

6.7.9.2Port J Data Direction Register (PTJDD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTJDD7

PTJDD6

PTJDD5

PTJDD4

PTJDD3

PTJDD2

PTJDD1

PTJDD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

Figure 6-51. Port J Data Direction Register (PTJDD)

 

Table 6-48. PTJDD Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTJDDn

reads.

 

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

 

1 Output driver enabled for port J bit n and PTJD reads return the contents of PTJDn.

 

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

 

 

138

Freescale Semiconductor

 

Get the latest version from freescale.com

Page 138
Image 138
Freescale Semiconductor MCF51QE128RM Port J Registers, Port J Data Register Ptjd, Port J Data Direction Register Ptjdd