Acr, Isr | Motorola MC68340 specification

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7.4.1.11AUXILIARY CONTROL REGISTER (ACR). The ACR selects which baud rate is used and controls the handshake of the transmitter/receiver. This register can only be written when the serial module is enabled (i.e., the STP bit in the MCR is cleared).

	ACR							$714
	7	6	5	4	3	2	1	0
	BRG	0	0	0	0	0	IECB	IECA
	RESET:
	0	0	0	0	0	0	0	0
	Write Only					Supervisor/User
BRG—Baud Rate Generator Set Select
1 =	Set 2 of the available baud rates is selected.
0 =	Set 1 of the available baud rates is selected. Refer to 7.4.1.6 Clock-Select
	Register (CSR) for more information on the baud rates.

IECB, IECA—Input Enable Control

1 = ISR bit 7 will be set and an interrupt will be generated when the corresponding bit in the IPCR (COSB or COSA) is set by an external transition on the channel's CTS≈ input (if bit 7 of the interrupt enable register (IER) is set to enable interrupts).

0 = Setting the corresponding bit in the IPCR has no effect on ISR bit 7.

7.4.1.12INTERRUPT STATUS REGISTER (ISR). The ISR provides status for all potential

interrupt sources. The contents of this register are masked by the IER. If a flag in the ISR is set and the corresponding bit in IER is also set, the IRQ≈ output is asserted. If the corresponding bit in the IER is cleared, the state of the bit in the ISR has no effect on the output. This register can only be read when the serial module is enabled (i.e., the STP bit in the MCR is cleared).

NOTE

The IER does not mask reading of the ISR. True status is provided regardless of the contents of IER. The contents of ISR are cleared when the serial module is reset.

ISR							$715
7	6	5	4	3	2	1	0
COS	DBB	RxRDYB TxRDYB		XTAL_	DBA	RxRDYA TxRDYA
				RDY
RESET:
0	0	0	0	1	0	0	0
Read Only					Supervisor/User

COS—Change-of-State

1 = A change-of-state has occurred at one of the CTS≈ inputs and has been selected to cause an interrupt by programming bit 1 and/or bit 0 of the ACR.

0 = The CPU32 has read the IPCR.

7- 32MC68340 USER’S MANUALMOTOROLA

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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.

Motorola MC68340 manual Acr, Isr

Models: MC68340

Freescale Semiconductor, Inc...

Freescale Semiconductor, Inc.

ACR

ISR

MC68340 specifications