General
Review and verify the
following for the custom board schematic design:
- Provision for isolating the circuit sections.
- Provision to external debug interface.
Schematic
Review
Follow the below list for
the custom schematic design:
- The recommendation is to add provision to isolate the
IOs that can be used for debug from alternate
function.
- Provision to connect the debug UARTs have been
provided (UART0, MCU_UART0, WKUP_UART0). The
recommendation is to add provision for connecting
UART interfaces for debug during initial board
build.
- The recommendation is to add provision for JTAG
connector or Test points for JTAG interface signals.
The recommendation is to place the pulls as per pin
connectivity requirements near to the processor JTAG
interface pins.
- The
required pullup and series resistors are provided
for the UART interface signals.
- External ESD protection provision added when external
interface signals are directly connected to the
processor UART signals. The recommendation is to add
provision for external ESD protection for the JTAG
interface signals.
Additional
- A number of
processor IOs including UARTs are not fail-safe. The
recommendation is to connect external inputs only after the
processor supplies ramps.
- The
recommendation is to disconnect the external interface
signals in case the processor board is powered off.
Refer below FAQ:
[FAQ] SK-AM62: Purpose Of
Different UARTs
The FAQ is generic and can also be used for AM625, AM623, AM620-Q1,
AM625-Q1, AM625SIP processor family.