Chapter 6 Parallel Input/Output Control

 

Table 6-24. PTED Register Field Descriptions

 

 

Field

Description

 

 

7–0

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

PTEDn

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

 

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

 

the corresponding MCU pin.

 

Reset forces PTED 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.

 

 

6.7.5.2Port E Data Direction Register (PTEDD)

R

W

Reset:

7

6

5

4

3

2

1

0

PTEDD7

PTEDD6

PTEDD5

PTEDD4

PTEDD3

PTEDD2

PTEDD1

PTEDD0

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

Figure 6-28. Port E Data Direction Register (PTEDD)

 

 

Table 6-25. PTEDD Register Field Descriptions

 

 

 

Field

 

Description

 

 

7–0

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

PTEDDn

reads.

 

0

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

 

1

Output driver enabled for port E bit n and PTED reads return the contents of PTEDn.

 

 

 

6.7.5.3Port E Data Set Register (PTESET)

7

6

5

4

3

2

1

0

R

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

W

 

PTESET7

PTESET6

PTESET5

PTESET4

PTESET3

PTESET2

PTESET1

PTESET0

 

 

 

 

 

 

 

 

 

 

 

Reset:

0

0

0

0

0

0

0

0

 

 

 

 

Figure 6-29. Port E Data Set Register (PTESET)

 

 

 

 

 

 

Table 6-26. PTESET Register Field Descriptions

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

Description

 

 

 

 

 

 

7–0

 

Data Set for Port E Bits. Writing 1 to any bit in this location sets the corresponding bit in the data register. Writing

PTESETn

a zero to any bit in this register has no effect.

 

 

 

 

 

 

 

0 Corresponding PTEDn maintains current value.

 

 

 

 

 

 

 

1 Corresponding PTEDn is set.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MCF51QE128 MCU Series Reference Manual, Rev. 3

Freescale Semiconductor

129

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Image 129
Freescale Semiconductor MCF51QE128RM Port E Data Direction Register Ptedd, Port E Data Set Register Pteset, PTEDD7 PTEDD6