Table of Contents
Advertisement
Bootstrapping
Approximate routing distances computed assuming a typical 140 ps/inch propagation delay in
50-Ω FR4 Microstrip or Stripline transmission lines. A 2D field solver or appropriate closed-form
approximate impedance equations should be used to find more exact propagation delay for a specific
given stackup and routing.
It is recommended that the QSPI memory be co-located close to the AM263x BGA footprint, which allows for
routing that maximizes the delay margins and skew margins. As seen in
include a series termination resistor near the QSPI controller clock transmit pin. Similarly, series terminations
should be added at the data pins of the QSPI device as well. During read quad-read operations, which will be the
most used mode of operation of the memory, this helps create well controlled edges on the data lines.
5.3 ROM QSPI Boot Requirements
For the AM263x device, ROM code expects the following QSPI flash memory features:
•
The flash device should be compatible with 3.3V LVCMOS signaling levels provided by the AM263x device
•
Ensure the flash device is set to write-protect mode disabled and hold-mode disabled.
– This is usually a pull-up resistor option on the D1 and D2 pins of the flash device.
– Ensure proper pull-up resistors are applied such that this correct operating state is selected.
•
The flash device be able to support Quad Output Fast Read (opcode 0x6B)
•
Flash must be able to support Fast Read in Single Mode (opcode 0x0B)
•
Device should allow 8 "dummy" clock cycles for setting up the initial address during the previously mentioned
read operations
•
Flash must support 3-byte (24 bit) addressing mode by default
•
Flash memory size should be in the 2.5MB-4MB range, but it is not recommended to exceed the 16MB range
to ensure correct operation
The following list of flash memory devices have been tested with the AM263x MCU for compatibility. For the
above compatibility requirements, check the specific flash device-specific data sheet.
For more information concerning QSPI flash memory compatibility, see the
Guide.
Table 5-3. AM263x QSPI Routing Rules Used on controlCard EVM
Manufacturer
Infineon
Winbond
GigaDevice
Macronix
The S25FL128SAGNFI000 devices from Infineon were utilized on the AM263x controlCard and
LaunchPad EVM.
6 JTAG Emulators and Trace
The AM263x MCU supports multiple different classes of JTAG emulators with or without additional ARM Trace
capture capabilities.
For out of box convenience the LP-AM263 and TMDSCNCD263 EVM designs implement an onboard XDS110
emulator with JTAG and auxiliary UART-USB bridge is implemented with a TI TM4C MCU and high-voltage
isolation. However, for actual custom systems, a simpler JTAG/Trace debug header should be implemented.
This allows for external JTAG and Trace pods to be attached to the system as needed during development. The
header can then be removed entirely or depopulated for full production of the system to save cost.
One popular, JTAG and Trace implementation is the MIPI industry standard MIPI-60 shown in [7]. This is based
on the Samtec QSH-030-01-L-D-A. This implementation is compatible with TI XDS560v2 JTAG/Trace pods as
well as other third-party JTAG/Trace pods. Additional, TI JTAG debugger connections can be found in [8].
24
AM263x Hardware Design Guide
Note
Flash Memory Devices
S25FL128S/S25FL256S series
W25Q series
GD25 series
MX25xxx35 series
Note
Copyright © 2022 Texas Instruments Incorporated
Figure
5-6, it is also recommended to
AM263x QSPI Flash Selection
SPRABJ8 – SEPTEMBER 2022
Submit Document Feedback
www.ti.com
Advertisement
Table of Contents
