Motorola MCF5281 Chip Select, Power Management, General Input/Output Ports, Sdram Controller

Models: MCF5282 MCF5281

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MCF5282 Key Features

1.1.4Chip Select

Programmable chip select outputs provide a glueless connection to external memory and peripheral circuits, providing all handshaking and timing signals for automatic wait-state insertion and data bus sizing.

1.1.5Power Management

The MCF5282 incorporates several low-power modes of operation which are entered under program control and exited by several external trigger events. An integrated Power-On Reset (POR) circuit monitors the input supply and forces an MCU reset as the supply voltage rises. The Low Voltage Detect (LVD) section monitors the supply voltage and is configurable to force a reset or interrupt condition if it falls below the LVD trip point. The RAM standby switch provides power to RAM when the supply voltage is higher than the standby voltage. If the supply voltage to chip falls below the standby battery voltage, the RAM is switched over to the standby supply.

1.1.6General Input/Output Ports

All of the pins associated with the external bus interface may be used for several different functions. Their primary function is to provide an external memory interface to access off-chip resources. When not used for this function, all of the pins may be used as general-purpose digital I/O pins. In some cases, the pin function is set by the operating mode, and the alternate pin functions are not supported.

The digital I/O pins on the MCF5282 are grouped into 8-bit ports. Some ports do not use all eight bits. Each port has registers that configure, monitor, and control the port pins.

1.1.7Interrupt Controllers (INTC0/INTC1)

There are two interrupt controllers on the MCF5282, each of which can support up to 63 interrupt sources for a total of 126. Each interrupt controller is organized as 7 levels with 9 interrupt sources per level. Each interrupt source has a unique interrupt vector, and 56 of the 63 sources of a given controller provide a programmable level [1-7] and priority within the level.

1.1.8SDRAM Controller

The SDRAM controller provides all required signals for glueless interfacing to a variety of JEDEC-compliant SDRAM devices. SRAS/SCAS address multiplexing is software configurable for different page sizes. To maintain refresh capability without conflicting with concurrent accesses on the address and data buses, SRAS, SCAS, DRAMW, SDRAM_CS[1:0], and SCKE are dedicated SDRAM signals.

MOTOROLA

Chapter 1. Overview

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Motorola MCF5281, MCF5282 Chip Select, Power Management, General Input/Output Ports, Interrupt Controllers INTC0/INTC1