Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

4.3.5.5PORT B PIN ASSIGNMENT REGISTER (PPARB). PPARB controls the function of each port B pin. Any set bit defines the corresponding pin to be an IRQ≈ input or CS≈

as defined in Table 4-5. Any cleared bit defines the corresponding pin to be a discrete I/O pin (or CS≈ if the FIRQ bit of the MCR is zero) controlled by the port B data and data direction registers. The MODCK signal has no function after reset. PPARB is configured to all ones at reset to provide for MODCK, IRQ7, IRQ6, IRQ5, IRQ3, and CS3–CS0. This register can be read or written at any time.

PPARB

 

 

 

 

 

$01F

7

6

5

4

3

2

1

0

PPARB7

PPARB6

PPARB5

PPARB4 PPARB3 PPARB2 PPARB1 PPARB0

(IRQ7)

(IRQ6)

(IRQ5)

(IRQ4)

(IRQ3)

(IRQ2)

(IRQ1)

(MODCK)

RESET:

 

 

 

 

 

 

 

1

1

1

1

1

1

1

1

Supervisor Only

4.3.5.6PORT B DATA DIRECTION REGISTER (DDRB). DDRB controls the direction of the pin drivers when the pins are configured as I/O. Any set bit configures the corresponding pin as an output; any cleared bit configures the corresponding pin as an input. This register affects only pins configured as discrete I/O. This register can be read or written at any time.

DDRB

 

 

 

 

 

 

$01D

7

6

5

4

3

2

1

0

DD7

DD6

DD5

DD4

DD3

DD2

DD1

DD0

RESET:

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

Supervisor/User

4.3.5.7PORT B DATA REGISTER (PORTB, PORTB1). This is a single register that can be accessed at two different addresses. This register affects only those pins configured as discrete I/O. A write is stored in the internal data latch, and if any port B pin is configured as an output, the value stored for that bit is driven on the pin. A read of this register returns the value stored in the register only if the pin is configured as a discrete output. Otherwise, the value read is the value of the pin. This register can be read or written at any time.

PORTB, PORTB1

 

 

 

$019, 01B

7

6

5

4

3

2

1

0

P7

P6

P5

P4

P3

P2

P1

P0

RESET:

 

 

 

 

 

 

 

U

U

U

U

U

U

U

U

Supervisor/User

MOTOROLAMC68340 USER’S MANUAL4- 35

For More Information On This Product,

Go to: www.freescale.com

Page 131 Page 133
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Image 132
Motorola MC68340 manual $01F, PORTB, PORTB1
Page 131 Page 133

MC68340 specifications

The Motorola MC68340 is a highly integrated microprocessor that was introduced in the early 1990s. It belongs to the 68000 family of microprocessors and is designed to cater to the demands of embedded systems, particularly in telecommunications and networking applications. This chip represents a significant evolution in microprocessor technology by combining a microprocessor core with additional peripherals on a single chip, making it an attractive solution for engineers looking to design compact and efficient systems.

One of the key features of the MC68340 is its 32-bit architecture, which allows for significant processing power and data handling capabilities. This architecture enables the processor to handle larger data sizes and perform more complex calculations compared to its 16-bit predecessors. The MC68340 operates at clock speeds typically ranging from 16 MHz to 25 MHz. Its dual instruction pipeline enhances throughput, allowing for simultaneous instruction fetches and executions, which significantly boosts performance.

A notable characteristic of the MC68340 is the inclusion of integrated peripherals, which help reduce the overall component count in a system. Key integrated components include a memory management unit (MMU), a direct memory access (DMA) controller, and various communication interfaces such as serial ports. The memory management capabilities enhance the processor's ability to manage memory resources efficiently, enabling it to support multitasking environments commonly found in modern computing.

In terms of connectivity, the MC68340 features connections for both synchronous and asynchronous serial communication, making it well-suited for networking tasks. The processor supports a range of bus standards, including address and data buses, which facilitate seamless interaction with peripheral devices.

Another important aspect of the MC68340 is its flexibility. The processor supports multiple operating modes, including multiple CPU configurations and compatibility with the Motorola 68000 family, allowing for easier integration into existing systems.

Moreover, the MC68340 boasts low power consumption compared to many of its contemporaries, making it an excellent choice for battery-operated applications, enhancing its appeal in sectors like telecommunications, industrial control, and automotive systems. Its combination of performance, integration, versatility, and efficiency has secured the MC68340 a reputable position in the annals of embedded systems technology, proving to be a valuable asset for developers and engineers alike.
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