Datasheet

www.ti.com

Hibernate, Current Shunts, Power Supplies, Reset and Crystals (Schematic page 3)

2.2.7 OLED Display

The development board includes a 96 x 64 color Organic LED (OLED) display. The OLED display is

powered from the on-board 13 V regulator, which must be enabled before using the display.

Data is written to the display using the SSI2 peripheral. Table 2-9 shows the signals used by the display.

Table 2-9. OLED Display Signals

GPIO Pin Pin Function OLED Function

PH7 SSI2TX SDIN

PH5 SSI2FSS CS

PH4 SSI2CLK SCLK

PH6 GPIO D/C

PG1 GPIO RST

PG0 GPIO +13VEN

2.2.8 SD Card

The DK-TM4C123G features a microSD card slot. Table 2-10 shows the signals used with the SD card.

Table 2-10. SD Card Signals

GPIO Pin Pin Function SD Card Function

PA5 SSI0TX DI

PA4 SSI0RX DO

PA3 SSI0FSS CS

PA2 SSI0CLK CLK

2.3 Hibernate, Current Shunts, Power Supplies, Reset and Crystals (Schematic page 3)

2.3.1 Hibernate

The DK-TM4C123G provides a 32.768 kHz crystal (Y1) as the clock source for the TM4C123GH6PGE’s

Hibernation module. Along with a 3.0-V CR2032 lithium coin-cell backup battery that is connected to the

VBAT pin and provides power to the Hibernation module when the microcontroller is in Hibernate mode.

The current draw while in Hibernate mode can be measured indirectly by measuring the voltage across

the 1-kΩ current shunt resistor. See Current Shunt Resistors for more details.

Several conditions can generate a wake signal to the Hibernate module; waking on a Real-time Clock

(RTC) match, waking on low battery, and/or waking on assertion of the WAKE pin.

(1)

The SELECT/WAKE

switch is connected to the WAKE pin on the microcontroller. When the microcontroller is configured to

wake on WAKE assertion, the switch can be used to wake the part from Hibernate mode. The

SELECT/WAKE switch is also connected to PM4 by way of a diode to prevent PM4 from asserting WAKE

when the part enters Hibernate mode. See Appendix A: Schematics for details.

To achieve the lowest power consumption while in Hibernate mode, the HIB signal is connected to the

Channel 1 Enable (EN1) signal of the Texas Instruments TPS2052B load switch (U7). In Hibernate mode,

the HIB signal is asserted and the load switch cuts main power to the entire board, excluding the on-board

ICDI. The Hibernation module is powered solely by the back-up battery.

(1)

If the board does not turn on when you connect it to a power source, the microcontroller might be in Hibernate mode (depending on the

programmed applications). You must satisfy one of the programmed wake conditions and connect the power to bring the microcontroller

out of Hibernate mode and turn on the board.

SPMU357B–August 2013–Revised March 2014 Hardware Description

Submit Documentation Feedback