Freescale Semiconductor MCF51QE128RM manual Port B Pull Enable Register Ptbpe

Models: MCF51QE128RM

1 424
Download 424 pages 63.71 Kb
Page 122
Image 122

Chapter 6 Parallel Input/Output Control

 

 

Table 6-7. PTBDD Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

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

PTBDDn

reads.

 

0

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

 

1

Output driver enabled for port B bit n and PTBD reads return the contents of PTBDn.

 

 

 

6.7.2.3Port B Pull Enable Register (PTBPE)

The port B pull enable register enables pull-ups on the corresponding PTB pin. In some cases, a pull-down device is enabled if pull-downs are supported by an alternate pin function (e.g., KBI).

R

W

Reset:

7

6

5

4

3

2

1

0

PTBPE7

PTBPE6

PTBPE5

PTBPE4

PTBPE3

PTBPE2

PTBPE1

PTBPE0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

Figure 6-11. Internal Pull Enable for Port B Register (PTBPE)

 

 

Table 6-8. PTBPE Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

Internal Pull Enable for Port B Bits. Each of these control bits determines if the internal pull-up or pull-down device

PTBPEn

is enabled for the associated PTB pin. For port B pins configured as outputs, these bits have no effect and the

 

internal pull devices are disabled.

 

0

Internal pull-up/pull-down device disabled for port B bit n.

 

1

Internal pull-up/pull-down device enabled for port B bit n.

 

 

 

6.7.2.4Port B Slew Rate Enable Register (PTBSE)

R

W

Reset:

7

6

5

4

3

2

1

0

PTBSE7

PTBSE6

PTBSE5

PTBSE4

PTBSE3

PTBSE2

PTBSE1

PTBSE0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

Figure 6-12. Slew Rate Enable for Port B Register (PTBSE)

 

 

Table 6-9. PTBSE Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

Output Slew Rate Enable for Port B Bits. Each of these control bits determines if the output slew rate control is

PTBSEn

enabled for the associated PTB pin. For port B pins configured as inputs, these bits have no effect.

 

0

Output slew rate control disabled for port B bit n.

 

1

Output slew rate control enabled for port B bit n.

 

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

122

Freescale Semiconductor

Get the latest version from freescale.com

Page 122
Image 122
Freescale Semiconductor MCF51QE128RM manual Port B Pull Enable Register Ptbpe, Port B Slew Rate Enable Register Ptbse