Gpios - NXP Semiconductors QorIQ LS1028A Reference Manual

The UART2 interface can be used to communicate either with mikro-click modules or
with RS232 compliant devices using the LTC2804-1 transceiver. The selection is done
through a mux which is controlled through the CFG_MUX_UART2_SEL0 signal by
CPLD.
Since the mikro-click modules operate at 3.3 V power supply, the CPLD enables the level
translator, SN74AVC2T245 (from Texas) to translate 1.8 V to 3.3 V voltage for the
selected module.
The following table describes configuration for accessing mikro-click modules on
mikroBUS1 or mikroBUS2 through SPI3/UART2/PWM interface.
Table 2-15. SPI3/UART2/PWM selection on mikro-click modules
CPLD signals
CFG_MUX_uBUS1_SPI_B
CFG_MUX_uBUS2_SPI_B
CFG_MUX_UART2_SEL0
CFG_MUX_uBUS1_UART_B
CFG_MUX_uBUS2_UART_B
CFG_MUX_uBUS1_PWM_B
CFG_MUX_uBUS2_PWM_B
Also, the mikro-click modules on mikroBUS1 or mikroBUS2 can be accessed directly
through I2C1 channel 6 or channel 7, respectively.

2.17 GPIOs

The two GPIOs used on the LS1028ARDB are GPIO1_24 and GPIO1_25. Apart from
these two GPIOs, all signals (UART, SPI, PWM) coming on connectors (mikro-click
module) can also act as GPIO signals.
GPIO1_DAT24 controls the VDD regulator and is used to change the VDD value from
1.0 V to 0.9 V as described in the following table.
GPIO
GPIO1_24
GPIO1_24
QorIQ LS1028A Reference Design Board Reference Manual, Rev. A, 02/2018
NXP Semiconductors
Registers
BRDCFG3[6]
BRDCFG3[5:4]
BRDCFG3[7]
Table 2-16. GPIO1_24 setting
Setting
High (default)
Low
Confidential Proprietary
Chapter 2 LS1028ARDB Functional Description
Configuration
0: SPI3 routed to mikroBUS1 module.
1: SPI3 routed to mikroBUS2 module.
0X: UART2 routed to RS232 transceiver and
DB9 connector P1A (default).
10: UART2 routed to mikroBUS1 module.
11: UART2 routed to mikroBUS2 module.
0: PWM (FTM1_CH1) routed to mikroBUS1
module.
1: PWM (FTM1_CH1) routed to mikroBUS2
module.
VDD
1.0 V
0.9 V
45