16-Bit Microcontroller with Infrared Module

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Detailed Description

The MAXQ61H microcontroller provides integrated,

low-cost solutions that simplify the design of IR commu-

nications equipment such as universal remote controls.

Standard features include the highly optimized, single-

cycle, MAXQ 16-bit RISC core, 36KB of user ROM

memory, 1.28KB data RAM, a soft stack, 16 general-

purpose registers, and three data pointers. The MAXQ

core offers the industry’s best MIPS/mA rating, allowing

developers to achieve the same performance as com-

peting microcontrollers at substantially lower clock

rates. Combining reduced active-mode current with the

MAXQ61H stop-mode current (0.2µA, typical) results in

increased battery life. Application-specific peripherals

include flexible timers for generating IR carrier frequen-

cies and modulation, a high-current IR drive pin capa-

ble of sinking up to 25mA current, and output pins

capable of sinking up to 5mA ideal for IR applications,

general-purpose I/O pins ideal for keypad matrix input,

and a power-fail-detection circuit to notify the applica-

tion when the supply voltage is nearing the minimum

operating voltage of the microcontroller.

At the heart of the MAXQ61H is the MAXQ 16-bit RISC

core. The MAXQ61H operates from DC to 12MHz and

almost all instructions execute in a single clock cycle

(83.3ns at 12MHz), enabling nearly 12MIPS true code

operation. When active device operation is not

required, an ultra-low-power stop mode can be invoked

from software, resulting in quiescent current consump-

tion of less than 0.2µA (typ) and 2.0µA (max). The com-

bination of high-performance instructions and ultra-low

stop-mode current increases battery life over compet-

ing microcontrollers. An integrated POR circuit with

brownout support resets the device to a known condi-

tion following a power-up cycle or brownout condition.

Additionally, a power-fail warning flag is set and a

power-fail interrupt can be generated when the system

voltage falls below the power-fail warning voltage,

cation to notify the user that the system supply is low

and appropriate action should be taken.

Microprocessor

The MAXQ61H is based on Maxim’s low-power, 16-bit

MAXQ family of RISC cores. The core supports the

Harvard memory architecture with separate 16-bit pro-

gram and data address buses. A fixed 16-bit instruction

word is standard, but data can be arranged in 8 or 16

bits. The MAXQ core in the MAXQ61H family is imple-

mented as a pipelined processor with performance

approaching 1MIPS/MHz. The 16-bit data path is imple-

mented around register modules, and each register

module contributes specific functions to the core. The

accumulator module consists of sixteen 16-bit registers

and is tightly coupled with the arithmetic logic unit

(ALU). A configurable soft stack supports program flow.

Execution of instructions is triggered by data transfer

between functional register modules or between a func-

tional register module and memory. Because data

movement involves only source and destination mod-

ules, circuit-switching activities are limited to active

modules only. For power-conscious applications, this

approach localizes power dissipation and minimizes

switching noise. The modular architecture also provides

a maximum of flexibility and reusability that is important

for a microprocessor used in embedded applications.

The MAXQ instruction set is highly orthogonal. All arith-

metical and logical operations can use any register in

conjunction with the accumulator. Data movement is

supported from any register to any other register.

Memory is accessed through specific data-pointer reg-

isters with automatic increment/decrement support.

Memory

The MAXQ61H incorporates several memory types that

include the following:

• 36KB user ROM

• 1.28KB SRAM data memory

• 1.024KB utility ROM

• Soft stack

Block Diagram

16-BIT MAXQ

RISC CPU

8kHz NANO

RING

1.28KB SRAM

IR TIMER

36KB USER ROM

SECURE MMU

16-BIT TIMER

16-BIT TIMER

GPIO

VOLTAGE

MONITOR

IR DRIVER

REGULATOR

WATCHDOG

CLOCK

1.024KB ROM

MAXQ61H