ATmega64A单片机详解：高性能低功耗微控制器

需积分: 18 114 浏览量更新于2024-07-24 1 收藏 7.79MB PDF 举报

"atmega64a是一款高性能、低功耗的AVR 8位微控制器，具有先进的RISC架构和丰富的内存及外设功能。" ATmega64A是Atmel公司生产的一款微控制器，其核心是基于AVR RISC（Reduced Instruction Set Computer）架构的8位处理器。RISC架构以其高效能和低功耗的特点，使得ATmega64A成为许多嵌入式系统设计的理想选择。这款芯片拥有以下关键特性： 1. **高性能与低功耗**：AVR处理器能在单个时钟周期内执行大部分指令，最大工作频率可达16MHz，提供了高达16MIPS的吞吐量。同时，它的静态操作模式有助于在待机状态下降低功耗。 2. **内存配置**：芯片内置了64KB的在系统可编程（ISP）Flash程序存储器，用于存储程序代码。此外，还有2KB的EEPROM，用于非易失性数据存储，以及4KB的内部SRAM，作为工作内存。Flash和EEPROM分别支持10,000次和100,000次的写入/擦除循环，并能保证在特定环境温度下长时间的数据保留。 3. **内存扩展**：ATmega64A还支持最多64KB的外部内存空间，以满足更大存储需求。 4. **编程与安全**：通过芯片内置的Boot Program功能实现在系统编程，并具有独立的锁定位，增强了软件安全。SPI接口用于ISP，而JTAG接口则提供IEEE 1149.1标准兼容的边界扫描能力，支持通过JTAG接口进行Flash、EEPROM、熔丝和锁定位的编程。 5. **外设功能**：包括两个带独立预分频器的8位定时器/计数器，以及多种其他外设如串行通信接口（SPI, I2C），多个模拟比较器，PWM输出等。这些外设增强了ATmega64A处理各种应用的能力。 6. **调试支持**：JTAG接口提供了广泛的片上调试支持，允许在运行过程中对程序进行实时调试，简化了开发流程。 7. **电源管理**：支持多种电源模式，可根据不同应用场景优化电源效率。 ATmega64A单片机以其强大的处理能力、丰富的内存配置和外设接口，广泛应用于消费电子、工业控制、汽车电子、智能家居等领域，是嵌入式系统设计中的常见选择。开发者可以利用其特性来构建高效、可靠的系统解决方案。

8160C–AVR–07/09

ATmega64A

When using the SEI instruction to enable interrupts, the instruction following SEI will be exe-

cuted before any pending interrupts, as shown in this example.

6.7 Interrupt Response Time

The interrupt execution response for all the enabled AVR interrupts is four clock cycles mini-

mum. After four clock cycles the program vector address for the actual interrupt handling routine

is executed. During this four clock cycle period, the Program Counter is pushed onto the Stack.

The vector is normally a jump to the interrupt routine, and this jump takes three clock cycles. If

an interrupt occurs during execution of a multi-cycle instruction, this instruction is completed

before the interrupt is served. If an interrupt occurs when the MCU is in sleep mode, the interrupt

execution response time is increased by four clock cycles. This increase comes in addition to the

start-up time from the selected sleep mode.

A return from an interrupt handling routine takes four clock cycles. During these four clock

cycles, the Program Counter (two bytes) is popped back from the Stack, the Stack Pointer is

incremented by two, and the I-bit in SREG is set.

Assembly Code Example

sei ; set global interrupt enable

sleep ; enter sleep, waiting for interrupt

; note: will enter sleep before any pending

; interrupt(s)

C Code Example

_SEI(); /* set global interrupt enable */

_SLEEP(); /* enter sleep, waiting for interrupt */

/* note: will enter sleep before any pending interrupt(s) */

8160C–AVR–07/09

ATmega64A

In ATmega103 compatibility mode, the first 4,096 data memory locations address both the Reg-

ister File, the I/O memory and the internal data SRAM. The first 32 locations address the

address the internal data SRAM.

An optional external data SRAM can be used with the ATmega64A. This SRAM will occupy an

area in the remaining address locations in the 64K address space. This area starts at the

address following the internal SRAM. The Register File, I/O, Extended I/O and internal SRAM

occupy the lowest 4,352 bytes in Normal mode, and the lowest 4,096 bytes in the ATmega103

compatibility mode (Extended I/O not present), so when using 64KB (65,536 bytes) of External

memory, 61,184 Bytes of External memory are available in Normal mode, and 61,440 Bytes in

ATmega103 compatibility mode. See “External Memory Interface” on page 23 for details on how

to take advantage of the external memory map.

When the addresses accessing the SRAM memory space exceeds the internal data memory

locations, the external data SRAM is accessed using the same instructions as for the internal

data memory access. When the internal data memories are accessed, the read and write strobe

pins (PG0 and PG1) are inactive during the whole access cycle. External SRAM operation is

enabled by setting the SRE bit in the MCUCR Register.

Accessing external SRAM takes one additional clock cycle per byte compared to access of the

internal SRAM. This means that the commands LD, ST, LDS, STS, LDD, STD, PUSH, and POP

take one additional clock cycle. If the Stack is placed in external SRAM, interrupts, subroutine

calls and returns take three clock cycles extra because the 2-byte Program Counter is pushed

and popped, and external memory access does not take advantage of the internal pipeline

memory access. When external SRAM interface is used with wait state, one-byte external

access takes two, three, or four additional clock cycles for one, two, and three wait states

respectively. Interrupt, subroutine calls and returns will need five, seven, or nine clock cycles

more than specified in the AVR Instruction Set manual for one, two, and three waitstates.

The five different addressing modes for the data memory cover: Direct, Indirect with Displace-

ment, Indirect, Indirect with Pre-decrement, and Indirect with Post-increment. In the Register

File, registers R26 to R31 feature the indirect addressing pointer registers.

The direct addressing reaches the entire data space.

The Indirect with Displacement mode reaches 63 address locations from the base address given

by the Y- or Z-register.

When using register indirect addressing modes with automatic pre-decrement and post-incre-

ment, the address registers X, Y, and Z are decremented or incremented.

The 32 general purpose working registers, 64 I/O Registers, 160 extended I/O Registers, and

the 4,096 bytes of internal data SRAM in the ATmega64A are all accessible through all these

addressing modes. The Register File is described in “General Purpose Register File” on page

12.

剩余391页未读，继续阅读

cj502277697

粉丝: 0
资源: 1

ATmega64A单片机详解：高性能低功耗微控制器

AVR单片机 atmega64单片机最小系统使用大全(含中文说明书)

AVR ATmega64 项目实例

ATMEGA64&128最小系统原理图.zip

ATmega128型号标识说明

ATMEGA64中文资料.pdf

ATMEGA128全套例程

AVR单片机系列ATmega64中文数据手册

自己整理的 单片机命名规则

ATmega单片机中文数据手册（ATmega8-16-32-64-128）

ATMega8最小系统原理图

最新资源

自己整理的单片机命名规则