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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 389
UG585 (v1.11) September 27, 2016
Chapter 14: General Purpose I/O (GPIO)
14.4.1 Clocks
The controller is clocked by the CPU_1x clock from the APB interface. All outputs and input sampling
is done using the CPU_1x clock.
For power management, clock gating can be employed on the GPIO controller clock using
slcr.APER_CLK_CTRL[GPIO_CPU_1XCLKACT].
14.4.2 Resets
The controller is reset by the slcr.GPIO_RST_CTRL [GPIO_CPU1X_RST] bit. Refer to Chapter 26, Reset
System
, for more information. This reset only affects the bus interface, not the controller logic itself.
14.4.3 Interrupts
The controller interrupts are explained in section 14.2.4 Interrupt Function. The controller asserts IRQ
# 52 to the GIC. A programming example is described in section
14.3.4 Reading Data from GPIO Input
Pins
.
14.5
I/O Interface
14.5.1 MIO Programming
Bank 0 and Bank 1 pins are routed through the MIO. These pins can be configured as GPIO using the
slcr.MIO_PIN_XX register.
Example: Configure MIO pin 6 as a GPIO signal
1. Select MIO pin as GPIO: Set L0_SEL, L1_SEL, L2_SEL, L3_SEL =0.
2. Set TRI_ENABLE = 0.
3. LVCMOS18 (refer to the register definition for other voltage options).
4. Slow CMOS edge.
5. Enable internal pull-up resistor.
6. Disable HSTL receiver.
Note: If TRI_ENABLE=1, then the output is 3-stated regardless of any GPIO settings. If
TRI_ENABLE=0, then 3-state is controlled by the gpio.OEN_x register.