Memory Map/Register Definition

Field

Reset

R/W:

Address

7

4

3

2

1

0

 

 

PORTn3

PORTn2

 

PORTn1

PORTn0

 

 

 

 

 

 

 

 

 

 

0000_1111

 

 

 

 

 

 

 

 

 

 

 

 

R

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

IPSBAR + 0x10_000F (PORTTC), 0x10_0010 (PORTTD), 0x10_0011 (PORTUA)

Figure 26-5. Port Output Data Registers (4-bit)

PORTn bits are described in Table 26-3.

Table 26-3. PORTn (8-bit, 7-bit, 6-bit, and 4-bit) Field Descriptions

Register

Bits

Name

Description

 

 

 

 

8-bit

7–0

PORTnx

Port output data bits.

 

 

 

1 Drives 1 when the port n pin is a digital output

7-bit

6–0

 

 

0 Drives 0 when the port n pin is a digital output

 

 

 

6-bit

5–0

 

 

 

 

 

 

4-bit

3–0

 

 

 

 

 

 

7-bit

7

Reserved, should be cleared.

 

 

 

 

6-bit

7–6

 

 

 

 

 

 

4-bit

7–4

 

 

 

 

 

 

26.3.2.2Port Data Direction Registers (DDRn)

The DDRs control the direction of the port n pin drivers when the pins are configured for digital I/O.

Most DDRs have a full 8-bit implementation, as shown in Figure 26-6.The remaining DDRs use fewer than eight bits. Their bit definitions are shown in Figure 26-7, Figure 26-8,and Figure 26-9.

The DDRs are read/write. At reset, all bits in the DDRs are cleared.

Setting any bit in a DDRn register configures the corresponding port n pin as an output. Clearing any bit in a DDRn register configures the corresponding pin as an input.

7

6

5

4

3

2

1

0

Field

DDRn7

DDRn6

DDRn5

DDRn4

 

DDRn3

DDRn2

DDRn1

DDRn0

 

 

 

 

 

 

 

 

 

Reset

 

 

 

0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

R/W:

 

 

 

 

R/W

 

 

 

 

 

Address

IPSBAR + 0x10_0014 (DDRA), 0x10_0015 (DDRB), 0x10_0016 (DDRC), 0x10_0017 (DDRD), 0x10_0018

 

 

(DDRE), 0x10_0019 (DDRF), 0x10_001A (DDRG), 0x10_001B (DDRH),

 

 

0x10_001C (DDRJ), 0x10_001D (DDRDD), 0x10_001E (DDREH), 0x10_001F (DDREL)

 

 

 

 

 

 

 

 

 

 

Figure 26-6. Port Data Direction Registers (8-bit)

MOTOROLA

Chapter 26. General Purpose I/O Module

26-9

Page 567
Image 567
Motorola MCF5281 Port Data Direction Registers DDRn, PORTn bits are described in Table, Register Bits Name Description