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LS1046A
DU
AR
T, D
VDD=3.3V
UART2_SIN, SOUT,
RTS2_B, CTS2_B
UART1_SIN, SOUT
UART
SEL
SW4[4]
CMSIS-DAP
1
0
RTS1_B, CTS1_B
J4
RS-232
PHY
RS-232
PHY
Figure 15. UART interface
The LS1046ARDB has two UART connectors; therefore, two UART ports are available at a time. Two RS-232 transceivers
(SP3232) available on the LS1046ARDB help in user application development and provide convenient communication channels
to both terminal and host computers. The transceivers are connected to the dedicated UART ports on the LS1046ARDB by 4
wires. They support RTS/CTS flow control. The SW4[4] controls the UART selection between PHY and CMSIS-DAP as given in
the table below.
Table 13. UART Selection
SW4[4] switch setting
Selection
ON
CMSIS-DAP
OFF
RJ45
The table below describes the LS1046ARDB RS-232 interface UART ports.
Table 14. LS1046ARDB RS-232 interface UART ports
UART port
Destination
Power supply
Flow control
External connector
UART1
Terminal (host
computer)
3.3 V
Supported
UART1 (J4 bottom)
UART2
Supported
UART2 (J4 top)
2.12 I2C interface
The LS1046A processor supports two I2C buses. The LS1046ARDB I2C has the following features:
• The LS1046A I2C1 is connected to the 4 KB EPPROM memory and temperature sensor
• The LS1046A I2C4 is connected to RTC and PCIe x1
• The level shifter device (PCA9306DCUR) is used on the LS1046ARDB I2C1 bus, to convert the LS1046A 3.3 V to 2.5 V
signals for the SPD
The figure below shows the overall I2C scheme connections.
I2C interface
QorIQ LS1046A Reference Design Board Reference Manual, Rev. 2, 30 May 2019
NXP Semiconductors
33