User manual TEXAS INSTRUMENTS STELLARIS LM3S1435 DATA SHEET REV D

[. . . ] TE X AS I NS TRUM E NTS - P RO DUCTION D ATA Stellaris® LM3S1435 Microcontroller D ATA SH E E T D S -LM 3S 1435 - 7 3 9 3 C opyri ght © 2007-2010 Texas Instruments Incorporated Copyright Copyright © 2007-2010 Texas Instruments Incorporated All rights reserved. Stellaris and StellarisWare are registered trademarks of Texas Instruments Incorporated. ARM and Thumb are registered trademarks and Cortex is a trademark of ARM Limited. Products conform to specifications per the terms of Texas Instruments standard warranty. [. . . ] For a level-sensitive interrupt, it is assumed that the external source holds the level constant for the interrupt to be recognized by the controller. Three registers are required to define the edge or sense that causes interrupts: GPIO Interrupt Sense (GPIOIS) register (see page 182) GPIO Interrupt Both Edges (GPIOIBE) register (see page 183) GPIO Interrupt Event (GPIOIEV) register (see page 184) Interrupts are enabled/disabled via the GPIO Interrupt Mask (GPIOIM) register (see page 185). When an interrupt condition occurs, the state of the interrupt signal can be viewed in two locations: the GPIO Raw Interrupt Status (GPIORIS) and GPIO Masked Interrupt Status (GPIOMIS) registers (see page 186 and page 187). As the name implies, the GPIOMIS register only shows interrupt 174 Texas Instruments-Production Data June 23, 2010 Stellaris® LM3S1435 Microcontroller conditions that are allowed to be passed to the controller. The GPIORIS register indicates that a GPIO pin meets the conditions for an interrupt, but has not necessarily been sent to the controller. In addition to providing GPIO functionality, PB4 can also be used as an external trigger for the ADC. If PB4 is configured as a non-masked interrupt pin (the appropriate bit of GPIOIM is set to 1), not only is an interrupt for PortB generated, but an external trigger signal is sent to the ADC. If the ADC Event Multiplexer Select (ADCEMUX) register is configured to use the external trigger, an ADC conversion is initiated. If no other PortB pins are being used to generate interrupts, the ARM Integrated Nested Vectored Interrupt Controller (NVIC) Interrupt Set Enable (SETNA) register can disable the PortB interrupts and the ADC interrupt can be used to read back the converted data. Otherwise, the PortB interrupt handler needs to ignore and clear interrupts on B4, and wait for the ADC interrupt or the ADC interrupt needs to be disabled in the SETNA register and the PortB interrupt handler polls the ADC registers until the conversion is completed. Interrupts are cleared by writing a 1 to the appropriate bit of the GPIO Interrupt Clear (GPIOICR) register (see page 188). When programming the following interrupt control registers, the interrupts should be masked (GPIOIM set to 0). Writing any value to an interrupt control register (GPIOIS, GPIOIBE, or GPIOIEV) can generate a spurious interrupt if the corresponding bits are enabled. 9. 1. 3 Mode Control The GPIO pins can be controlled by either hardware or software. When hardware control is enabled via the GPIO Alternate Function Select (GPIOAFSEL) register (see page 189), the pin state is controlled by its alternate function (that is, the peripheral). Software control corresponds to GPIO mode, where the GPIODATA register is used to read/write the corresponding pins. 9. 1. 4 Commit Control The GPIO commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. Protection is currently provided for the five JTAG/SWD pins (PB7 and PC[3:0]). Writes to protected bits of the GPIO Alternate Function Select (GPIOAFSEL) register (see page 189) are not committed to storage unless the GPIO Lock (GPIOLOCK) register (see page 199) has been unlocked and the appropriate bits of the GPIO Commit (GPIOCR) register (see page 200) have been set to 1. 9. 1. 5 Pad Control The pad control registers allow for GPIO pad configuration by software based on the application requirements. The pad control registers include the GPIODR2R, GPIODR4R, GPIODR8R, GPIOODR, GPIOPUR, GPIOPDR, GPIOSLR, and GPIODEN registers. These registers control drive strength, open-drain configuration, pull-up and pull-down resistors, slew-rate control and digital input enable. For special high-current applications, the GPIO output buffers may be used with the following restrictions. With the GPIO pins configured as 8-mA output drivers, a total of four GPIO outputs may be used to sink current loads up to 18 mA each. The high-current GPIO package pins must be selected such that there are only a maximum of two per side of the physical package or BGA pin group with the total number of high-current GPIO outputs not exceeding four for the entire package. June 23, 2010 Texas Instruments-Production Data 175 General-Purpose Input/Outputs (GPIOs) 9. 1. 6 Identification The identification registers configured at reset allow software to detect and identify the module as a GPIO block. [. . . ] 108-Ball BGA Package June 23, 2010 Texas Instruments-Production Data 541 Package Information Note: The following notes apply to the package drawing. Symbols A A1 A3 c D D1 E E1 b bbb ddd e f M n MIN 1. 22 0. 29 0. 65 0. 28 9. 85 NOM 1. 36 0. 34 0. 70 0. 32 10. 00 8. 80 BSC MAX 1. 50 0. 39 0. 75 0. 36 10. 15 9. 85 10. 00 8. 80 BSC 10. 15 0. 43 0. 48 . 20 . 12 0. 80 BSC 0. 53 - 0. 60 12 108 REF: JEDEC MO-219F - 542 Texas Instruments-Production Data June 23, 2010 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI's standard warranty. [. . . ]