AM57xx hardware
AM57xx hardware
The purpose of this guide is to walk hardware designers through the various stages of designing a board on this platform.
Trademarks
All trademarks are the property of their respective owners.
1 Introduction
This document follows the structure shown in Figure 1. Each design stage in the Timeline links to a collection of useful documentation, application reports, and design recommendations pertaining to that stage. Using this guide, hardware designers can efficiently locate the resources they need at every step in the board design flow.
Figure 1. Hardware Design Timeline 2 Constructing the Block Diagram
The first step in designing the hardware platform is to create a detailed block diagram. The block diagram should contain all major system ICs and illustrate which I/O ports are used for device interconnection. Below is a collection of resources to aid in the Block Diagram creation process.
- The links at the TI website below provide block diagrams, application reports, tools, software, design considerations, and other related information for various products under category "Related End Equipments".
- An EVM (Evaluation Module) is always a good source from which to start building a reference design for these devices. The technical documentation for the EVM is available for download from the following locations:
- The AM57xx family of devices offer a range of performance options while being all designed using the same processing elements and interfaces. This allows that family to be software compatible. Additionally, AM574x, AM572x and AM571x have very similar footprints that allow migration on the same board design. The AM574x/AM572x/AM571x Compatibility Guide covers the differences in ball assignment, pin multiplexing and basic features between AM574x, AM572x, and AM571x.
- Select from a list of complementary devices to attach to AM57xx device in your system:
3 Selecting the Boot Mode
The block diagram that you are creating should also indicate which interface will be used for booting this device. These devices contain an on-chip ROM bootloader with the following features:
- The boot config pins are sampled at power-on-reset
- Sets up system for boot depending on boot configuration selected
- Depending on boot mode, copies image to internal RAM and then executes it
- Maximum size of the boot image is 128 KBytes
The following boot modes are supported:
- NOR Flash boot
- NAND Flash boot
- SD boot
- eMMC boot
- QSPI_1 boot (1-bit SPI flash memories)
- QSPI_4 boot (4-bit (Quad) SPI flash memories)
- SATA boot
- Universal Asynchronous Receiver/Transmitter (UART) boot
- Universal Serial Bus (USB) boot (like an ethernet card, not as mass storage)
- HS USB 2.0 boot (like an ethernet card, not as mass storage)
If the first boot source fails to boot, the ROM will move on to the next one in the sequence. Keep in mind that some boot sources take some time to timeout if that boot source isn't available.
To understand details on different boot modes, see the device-specific technical reference manual (TRM).
Key Boot Considerations are:
- It is recommended to include population options for other boot modes to aid in development
- Boot pins have other functions after reset. Make sure your board design takes this into account when choosing pull-up/down resistors for the boot pins.
4 Confirming Pin Multiplexing Compatibility
The AM57xx device contains many peripheral interfaces. In order to reduce package costs while maintaining maximum functionality, many of the AM57xx terminals can multiplex up to 16 signal functions. Some background about the AM57xx pin-multiplexing:
- Although there are many combinations of pin-multiplexing that are possible, only a certain number of sets, called IO sets, are valid due to timing limitations. These valid IO sets were carefully chosen to provide many possible application scenarios for the user.
- In order to guarantee the IO timings published in the AM57xx data manual over the lifetime of the device, AM57xx software must implement the proper pin configuration requirements. These requirements impact software configuration of the following registers and are fully documented in the Pad Configuration section of the device-specific AM57xx TRM
- Pad Configuration Registers (muxmode, slew control, Virtual IO Timing Modes, and so forth)
- IODELAYCONFIG Registers (Manual IO Timing Modes)
Texas Instruments has developed a Windows/Linux application called the TI PinMux Tool that helps a system designer select the appropriate pin-multiplexing configuration for their AM57xx-based product design. This tool provides a way to select valid IO Sets of specific peripheral interfaces to insure the pin-multiplexing configuration selected for a design only uses valid IO Sets supported by AM57x. Additionally, it also provides generated output files to help software correctly implement the pad configuration requirements necessary for guaranteeing the device's IO timings. These generated files are named with the prefix "boardPadDelay." The TI PinMux Tool must be used to validate the device pin definitions chosen in your design. It can be accessed at the link below:
5 Confirming Electrical and Timing Compatibility
A key step in the hardware design before beginning schematic capture is to confirm both DC and AC electrical compatibility between this device and the other ICs connecting to it.
- The device data sheet has important information with regards to timing and electrical characteristics.
- For high-speed interfaces, you can run IBIS simulations using IBIS models provided for AM57x ZCE and ZCZ package to confirm signal Integrity. The IBIS model for your chosen AM57xx device can be downloaded from the Models section under the Tools & Software tab of the device's product page on ti.com.
- Using IBIS Models for Timing Analysis
- DDR3/DDR3L - see the device-specific data manual (precludes timing analysis)
- USB, HDMI, SATA, PCIe - see the High-Speed Interface Layout Guidelines
NOTE
TI provides PCB layout specifications for the following interfaces, eliminating the need to perform electrical analysis:
