Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

The reset value of the IARB field is $0, which prevents the DMA module from arbitrating during the interrupt acknowledge cycle. The system software should initialize the IARB field to a value from $F (highest priority) to $1 (lowest priority).

NOTE

The DMA module uses only one set of IARB bits for both channels. A read or write to either MCR accesses the same IARB control bits.

6.7.2 Interrupt Register (INTR)

The INTR contains the priority level for the channel interrupt request and the 8-bit vector number of the interrupt. The register can be read or written to at any time while in supervisor mode and while the DMA module is enabled (i.e., the STP bit in the MCR is cleared).

INTR1, INTR2

 

 

 

 

 

 

 

 

 

 

 

$784, $7A4

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

0

0

0

0

0

 

INTL

 

 

 

 

 

INTV

 

 

 

RESET:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

1

Supervisor Only

Bits 15–11—Reserved

INTL—Interrupt Level Bits

Each module that can generate interrupts has an interrupt level field. The interrupt level field contains the priority level of the interrupt for its associated channel. The priority level encoded in these bits is sent to the CPU32 on the appropriate IRQsignal. The CPU32 uses this value to determine servicing priority. See Section 5 CPU32 for more information.

INTV—Interrupt Vector Bits

Each module that can generate interrupts has an interrupt vector field. The interrupt vector field contains the vector number of the interrupt for its associated channel. This 8-bit number indicates the offset from the base of the vector table where the address of the exception handler for the specified interrupt is located. The INTV field is reset to $0F, which indicates an uninitialized interrupt condition. See Section 5 CPU32 for more information.

6.7.3 Channel Control Register (CCR)

The CCR controls the configuration of the DMA channel. This register is accessible in either supervisor or user space. The CCR can always be read or written to when the DMA module is enabled (i.e., the STP bit in the MCR is cleared).

6- 26MC68340 USER’S MANUALMOTOROLA

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Motorola MC68340 manual Interrupt Register Intr, Channel Control Register CCR, INTR1, INTR2

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.