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EMA_CS[0]
EMA_CAS
EMA_RAS
EMA_CLK
EMA_SDCKE
EMA_CS[5:2]
EMA_OE
EMA_WAIT
EMA_WE
EMA_BA[1:0]
EMA_WE_DQM[x:0]
EMA_D[x:0]
EMA_A[x:0]
EMIFA
CPU
EDMA
Master
Peripherals
SDRAM
interface
Asynchronous
interface
Shared SDRAM
and asynchronous
interface
EMA_A_RW
Introduction
835
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
External Memory Interface A (EMIFA)
19.1 Introduction
19.1.1 Purpose of the Peripheral
EMIFA memory controller is complaint with the JESD21-C SDR SDRAM memories utilizing 16-bit data bus
of EMIFA memory controller. The purpose of this EMIFA is to provide a means for the CPU to connect to
a variety of external devices including:
•
Single data rate (SDR) SDRAM
•
Asynchronous devices including NOR Flash, NAND Flash, and SRAM
The most common use for the EMIFA is to interface with both a flash device and an SDRAM device
simultaneously.
contains an example of operating the EMIFA in this configuration.
19.1.2 Features
The EMIFA includes many features to enhance the ease and flexibility of connecting to external SDR
SDRAM and asynchronous devices. For details on features of EMIFA, see your device-specific data
manual.
19.1.3 Functional Block Diagram
illustrates the connections between the EMIFA and its internal requesters, along with the
external EMIFA pins.
contains a description of the entities internal to the SoC that can send
requests to the EMIFA, along with their prioritization.
describes the EMIFA external pins
and summarizes their purpose when interfacing with SDRAM and asynchronous devices.
Figure 19-1. EMIFA Functional Block Diagram
19.2 Architecture
This section provides details about the architecture and operation of the EMIFA. Both, SDRAM and
asynchronous interface are covered, along with other system-related issues such as clock control and pin
multiplexing.
The EMIFA SDRAM interface is not supported on all devices, see your device-specific data manual to see
if the EMIFA SDRAM is supported on your device.