Freescale Semiconductor MCF51QE128RM manual Port C Registers, Port C Data Register Ptcd

Models: MCF51QE128RM

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Chapter 6 Parallel Input/Output Control

6.7.2.5Port B Drive Strength Selection Register (PTBDS)

R

W

Reset:

7

6

5

4

3

2

1

0

PTBDS7

PTBDS6

PTBDS5

PTBDS4

PTBDS3

PTBDS2

PTBDS1

PTBDS0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

Figure 6-13. Drive Strength Selection for Port B Register (PTBDS)

 

 

Table 6-10. PTBDS Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

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

PTBDSn

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

 

0

Low output drive strength selected for port B bit n.

 

1

High output drive strength selected for port B bit n.

 

 

 

6.7.3Port C Registers

Port C is controlled by the registers listed below.

6.7.3.1Port C Data Register (PTCD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTCD7

PTCD6

PTCD5

PTCD4

PTCD3

PTCD2

PTCD1

PTCD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

Figure 6-14. Port C Data Register (PTCD)

 

Table 6-11. PTCD Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTCDn

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

 

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

 

the corresponding MCU pin.

 

Reset forces PTCD 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.

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

Freescale Semiconductor

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Freescale Semiconductor MCF51QE128RM manual Port C Registers, Port B Drive Strength Selection Register Ptbds