ADLINK Technology arm AMPERE COM-HPC-ALT - I2 C

COM-HPC-ALT User’s Guide PICMG COM-HPC R1.0
Page 21 Copyright © 2023 ADLINK Technology, Inc.
The Module asynchronous serial ports should not be implemented as USB peripherals, as such implementations are generally not useful for low level
debug purposes.
The COM-HPC UART signals are “logic level” signals and are the logic inverse of what is on an RS-232 line. The “Mark” (logic 1) voltage level is nominally
3.3V on the COM-HPC line and the “Space” (logic 0) is nominally 0V. RS-232 transceivers (on the Carrier) invert the signals and change the levels – so
that a “Mark” is between -3V and -25V, and a “Space” is between +3V and +25V
In some situations, the UARTx_RTS# line can be used alternatively as an RS485 transmit enable line.
Name
Pin #
Description
I/O
PU / PD
Comment
UART0_TX
UART1_TX
C89
B87
Logic level asynchronous serial port transmit signal
O 3.3V
UART0_RX
UART1_RX
C90
B88
Logic level asynchronous serial port receive signal
I 3.3V
PU 10K
UART0_RTS#
UART1_RTS#
C91
B89
Logic level asynchronous serial port Request to Send
signal, active low
O 3.3V
UART0_CTS#
UART1_CTS#
C92
B90
Logic level asynchronous serial port Clear to Send
input, active low
I 3.3V
4.3.6 I2C
Two general purpose I2C ports are defined for COM-HPC. The first of the two supports an ALERT# input. The ports shall support 100KHz operation and
should 400KHz operation. The ports should be multi-master capable. I2C0 is defined to operate from a 3.3V rail and I2C1 from a 1.8V rail. The I2C1 port
may be I3C capable.
I2C source from Ampere Altra SOC supports multi-master